It comes from the golden spiral, a mathematical spiral which goes on forever, with ratio of 1:1.618. The golden ratio appears to be found in many works of art and often seen in nature, and observing it in nature is what allows you to spin things with a rotation close to the golden spiral. This tradition grants you access to steel balls, the main instrument of the Spin, and the many versatile implementations of it.

Steel Balls

Starting when you choose this tradition at 3rd level, you are able to craft the perfect vehicle for the Golden Spin: steel balls. By spending 1 hour and 1 sp worth of steel during a long rest, you are able to create a steel ball.

In order for your steel balls to gain the following benefits, you must attune to them and you can only attune to 2 steel balls at once. Attuning to your Steel Balls represents the time invested in maintaining them as perfect spheres ideal for using the spin. A steel ball's weight is 1lb.

For any creature that is not a Way of the Spin Monk, it counts as an improvised weapon. For you, it is treated as a thrown melee weapon (30/90) with which you are proficient and you also treat it as a monk weapon. A steel ball's damage die is 1d8 plus your Dexterity Modifier or your Martial Arts die, whichever is higher and it deals bludgeoning damage.

Spin Techniques

Additionally at 3rd level, you gain the ability to imbue objects with rotational energy. As a bonus action, you can apply the spin to 1 or 2 (expending 2 uses of this feature) objects which fit in your hand. For 10 minutes or until you end the spin as an action, the object(s) will continue to spin and gain special properties. When thrown, you can choose for a spinning object to immediately return to you and it can be used for spin techniques detailed below. You can use this feature a number of times up to your Wisdom Modifier (minimum of 1) and regain all expended uses when you finish a short or long rest.

Spin Techniques

When you make any use of an object which has the spinning property from your ability, you can cause special effects to occur by using spin techniques. At the end of every long rest, you can prepare 2 Spin Techniques from the list below and you lose the techniques you prepared at the end of your previous long rest. At 11th level, you can prepare 3 Spin Techniques instead of 2 at the end of a long rest. Some techniques refer to your Spin Save DC, which is equal to 8 + your Wisdom Modifier + your Proficiency Bonus. An object imbued with spin can only make use of 1 spin technique when you attack with it.

Contort

When you hit a creature with a spinning object, you can spend 1 ki point in order to attempt to contort its body. The creature must succeed on a strength saving throw against your Spin save DC or have disadvantage on all of its attacks until the end of your next turn.

Controlled Throw

When you throw one of your spinning objects, you can exercise greater control of it as it goes. When you make a ranged attack roll with an object imbued with spin, you can spend 1 ki point to give yourself advantage on the attack roll. You can choose to use this feature after you have rolled, but before you know whether the attack hits or misses.

Destructive Spin

When you hit a creature with a spinning object, you can spend 1 ki point to deal extra damage equal to your martial arts die. This damage is bludgeoning damage which counts as magical for the sake of overcoming resistances. You can spend more than 1 ki point to add additional martial arts dice, but you can only use this technique once on your turn. If you hit an object with this ability, you treat all damage rolls as being the maximum. The highest number of ki points you are able to spend on this is equal to your proficiency bonus.

Detection

Vibrations in your spinning object can allow you to examine the terrain ahead of you. When you throw a spinning object, you can choose to spend 1 ki point to detect all traps and hidden passages in a 50ft radius centred around the object.

Disarm

When you hit a creature with a spinning object, you can spend 1 ki point to try to disable its arm. The creature must succeed on a dexterity saving throw against your Spin save DC or drop the equipment from an arm of your choice and be unable to hold anything with that arm until the end of your next turn.

Skin Harden

You can harden your skin in order to be more resistant to enemy attacks. As a bonus action you can spend 1 ki to use a spinning object to give yourself a +2 bonus to your armour class for 1 minute. This effect ends if the object leaves you.

Spin Familiar

Starting from 3rd Level, you gain access to a familiar spirit awoken by the power of the Spin and sent to guide you on your path to mastery. Choose from the following options to see which spirit familiar you get, your choice which will change how your character uses the Spin in it's attacks. Your spirit is treated as a celestial familiar. In combat, it shares your initiative, and it is always present unless you dismiss it with an action. You can summon it with a free action, but if initiative starts without your Spin Familiar summoned, you will have to spend an Attack Action to summon it. If it takes damage, you take damage equal to half of the damage it took due to your link with it through your shared Spin. The damage your Spin Familiar's inflict is magical.

Ball Breaker

Small Celestial

Armor Class: 16 (Natural Armor)
Hit Points: 2 + your Dexterity Modifier + 4 times your Monk Level
Speed: 20 ft, fly 30 ft.
Statblock: STR 4 (-3) DEX 15 (+2) CON 12 (+1) INT 10 (+0) WIS 10 (+0) CHA 7 (-2)
Saving: Throws DEX +4
Skills: Perception +4, Stealth +4
Damage Immunities: Poison
Condition Immunities: Exhaustion, Poisoned
Senses: Darkvision 60 ft., Passive Perception 14
Languages: Understands the languages you speak
Challenge: -
Proficiency Bonus +2

Vigilant: Ball Breaker can't be surprised.

Evasion. If Ball Breaker is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails. It can't use this trait if it's incapacitated.

Actions:

Golden Spin: Ranged Weapon Attack: +4 to hit, range 60 ft., one target you can see using a Steel Ball. Hit: 1d8 + 5 force damage, you can spend a ki point to make the creature hit by this attack take additional bludgeoning damage equal to your Monk Level.

Bonus Actions:

Golden Spin: Ranged Weapon Attack: +4 to hit, range 60 ft., one target you can see using a Steel Ball. Hit: 1d8 + 5 force damage, you can spend a ki point to make the creature hit by this attack take additional bludgeoning damage equal to your Monk Level.


Tusk ACT 1

Small Celestial

Armor Class: 16 (natural armor)
Hit Points: 2 + your Wisdom modifier + 4 times your Monk level
Speed: Same Speed as your character.
Statblock: STR 4 (-3) DEX 15 (+2) CON 12 (+1) INT 10 (+0) WIS 10 (+0) CHA 7 (-2)
Saving Throws: Dex +2 plus PB, Con +2 plus PB
Skills: Athletics +2 plus PB, Perception +0 plus PB x 2
Damage Immunities: Poison
Condition Immunities: Charmed, Exhaustion, Poisoned
Senses: Darkvision 60 ft., Passive Perception 13 + (PB x 2)
Languages: understands the languages you speak
Challenge: —
Proficiency Bonus (PB): equals your bonus

Vigilant. Tusk can't be surprised.

Evasion. If Tusk is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails. It can't use this trait if it's incapacitated.

Actions:

Spinning Nail: Using Tusk ACT 1, you can imbue your own fingernails with the Spin and fire them like bullets. Ranged Weapon Attack: +4 to hit, range 120 ft, one target you can see. Hit: 1d6 + your Dex or Wis Mod force damage and 1d6 radiant damage.

It takes 1 minute to regrow 1 fingernail after this ability is used.

Spin-Empowered Steel Balls

Starting from 6th level, you gain a greater mastery over the Spin.

When you throw your steel balls, they always have some spin within them. Whenever you make a ranged or melee attack with a steel ball, it's damage counts as magical for the purpose of overcoming resistance and its thrown range increases to (60/90). Furthermore, you can choose for your steel balls to return to your hand if they hit your intended target.

Proficiencies:

As part of your greater mastery of Spin, you are able to use it as a medium for using tools precisely and effectively.

You gain proficiency in 1 tool set of your choice.
You gain proficiency in the medicine skill. If you already have proficiency in this skill, then choose 1 other skill to take proficiency in.

Spin Familiar Upgrade

At Level 6, your Spin Familiars gain an upgrade.

Ball Breaker:
+2 DEX.

Ball Breaker can target 2 creatures at once with it's Golden Spin Attack Action. It gains a Second Attack Action. Any creature that is hit by it's Golden Spin Attack must make a Dexerity Saving Throw against your Spin Save DC or they are knocked prone and must spend half their movement to get up again during their next turn.


Tusk ACT 1:

Tusk ACT 1 becomes Tusk ACT 2, evolving.

Tusk ACT 2 retains the same Stat Block as ACT 1 with the following additions:

+2 WIS.

Actions:

Tusk ACT 2 can take 2 Attack Actions.

Spinning Nail: Using Tusk, you can imbue your own fingernails with the Spin. Ranged Weapon Attack: +4 to hit, range 120 ft, one target you can see. Hit: 1d6 + Wis Mod force damage and 1d6 radiant damage.

Golden Rectangle Spin: You've learned to imbue your nail shots with the Golden Rectangle Spin, a more perfected form of Spin. Ranged Weapon Attack: +7 to hit, range 120 ft, one target you can see. Hit: 1d8 + your Dex or Wis Mod force damage and 1d8 radiant damage. You can spend up to 2 Ki Points to add an additional d6 of radiant damage to the shot for each Ki Point spent. If your nail hits the target, the creature must succeed on a Constitution saving throw against your Spin Save DC or they are stunned until the end of your familiar's next turn.

Golden Devastation

Starting from 11th Level, your control over the Spin becomes greater.

Mighty Arm - Your Steel Ball range becomes 200 feet and you can attack an opponent within 5 feet of you without disadvantage.
Wrecking Ball - As an action, you hurl multiple Steel Balls simultaneously at a point you choose within your current Steel Ball range, where it erupts into a blast of rotational energy for a brief but deadly instant. Each creature in that 15-foot-radius sphere must succeed on a Constitution saving throw or take 3d6 of force or radiant damage (your choice). Any creatures that fail the save are also Blinded and Deafened until the start of your next turn. You can increase the sphere’s damage by spending ki points. Each point you spend, to a maximum of 3, increases the damage by 2d6. You may use this feature twice before needing a short or long rest.

Spin Familiar Upgrade

At Level 11, your Spin Familiars gain a further upgrade.


Ball Breaker:
+2 CON, +40 HP.

Ball Breaker can now hit additional targets within 30 ft of the original target of it's Golden Spin Attack. You can spend 2 ki points to impose disadvantage on the Dexerity Saving Throw a creature must make against your Spin Save DC. Your opponent must now spend all their movement getting up from being knocked prone. If you spend ki points to impose disadvantage, the damage increases by 1d8 radiant damage for each ki point spent. If a creature is hit as an additional target by Ball Breaker's Golden Spin Attack, it takes an additional amount of damage equal to your Dexterity Modifier.

You can use your Bonus Action to make a Golden Spin Attack.


Tusk ACT 3:
Tusk ACT 2 becomes Tusk ACT 3, evolving further.
Tusk ACT 3 retains the same Stat Block as ACT 2 with the following additions:

+2 to DEX, +2 to CON.

Actions:

Spinning Nail: Using Tusk, you can imbue your own fingernails with the Spin. Ranged Weapon Attack: +9 to hit, range 120 ft, one target you can see. Hit: 1d8 + Wis Mod force damage and 2d6 radiant damage.

Golden Rectangle Spin: You've learned to imbue your nail shots with the Golden Rectangle Spin, a more perfected form of Spin. Ranged Weapon Attack: +9 to hit, range 120 ft, one target you can see. Hit: 1d10 + your Dex or Wis Mod force damage and 1d8 radiant damage. You can spend up to 2 Ki Points to add an additional d6 of radiant damage to the shot for each Ki Point spent. If your nail hits the target, the creature must succeed on a Constitution saving throw against your Spin Save DC or they are stunned until the start of your next turn.

Bonus Action:

Spatial Wormhole: After Awakening to ACT 3, you can now use the Golden Rectangle Spin to rip open spacetime and transport yourself and Tusk through a void created by the Spin. You can teleport yourself and Tusk into a space you can see up to 60 feet away from you by spending 2 ki points. If you teleport to a space occupied by a creature, you take 1d6 radiant damage and the creature takes 2d6 plus your Wisdom Modifier in radiant damage.

The Golden Spin

Starting from 17th level, you gain perfect mastery of the spin. You have found the golden ratio in nature and are able to utilise it to create the strongest possible spinning power.

You can spend 6 ki points when you throw one of your steel balls to imbue it with infinite spinning energy, gained from achieving a perfect golden ratio. When a target is hit by your infinitely spinning steel ball, they must make a strength saving throw against your Spin save DC with disadvantage. On a success, they take 10d12 bludgeoning damage which cannot be resisted and ignores immunity. On a failure, the target takes the same damage and becomes paralysed permanently.

This paralysis cannot be undone by any type of magic, due to the infinite nature of the attack. While they are paralysed, all the individual cells of their body spin independently and cause them to be unable to move. On each round that they are affected by the spin, they take 2 damage. If a creature is reduced to 0 hit points by the initial attack, the constant damage, or in any way while their body still spins, their body scatters into dust and they cannot be revived by anything other than a True Resurrection spell.

The only way to undo this effect on the creature is to hit them with infinite spin in the opposite direction to cancel out the effect. A creature is anchored to the point where they were hit while they are still spinning, and they cannot be transported to other planes or away from that point.

Spin Familiar Upgrade

At Level 17, your Spin Familiars gain a final upgrade as you master the Spin together.

Ball Breaker:
+40 HP, DEX 24.

Ball Breaker can now hit additional targets within 120 ft of the original target of it's Golden Spin Attack and can make 4 attacks per action. You can spend 1 ki points to impose disadvantage on the Dexerity Saving Throw a creature must make against your Spin Save DC. Your opponent must now spend all their movement getting up from being knocked prone. If you spend ki points to impose disadvantage, the damage increases by 3d8 radiant damage for each ki point spent. If a creature is hit as an additional target by Ball Breaker's Golden Spin Attack, it takes an additional amount of damage equal to your Dexterity Modifier plus your Proficiency Modifier.

You can use your Bonus Action to make two Golden Spin Attacks.


Tusk ACT 4:
Tusk ACT 3 becomes Tusk ACT 4, evolving further.
Tusk ACT 4 retains the same Stat Block as ACT 3 with the following additions:

+40 HP, WIS 24.

Actions:

Spinning Nail: Using Tusk, you can imbue your own fingernails with the Spin. Ranged Weapon Attack: +13 to hit, range 120 ft, one target you can see. Hit: 2d8 + Wis Mod force damage and 2d6 radiant damage.

Golden Rectangle Spin: You've learned to imbue your nail shots with the Golden Rectangle Spin, a more perfected form of Spin. Ranged Weapon Attack: +13 to hit, range 120 ft, one target you can see. Hit: 2d10 + your Dex or Wis Mod force damage and 2d8 radiant damage. You can spend up to 2 Ki Points to add an additional d8 of radiant damage to the shot for each Ki Point spent. If your nail hits the target, the creature must succeed on a Constitution saving throw against your Spin Save DC or they are stunned for 1 minute.

Infinite Golden Spin: The absoulte perfect state of the Spin, as manifested through Tusk ACT 4. Ranged Spell Attack: The target must make a Constitution saving throw against your Spin Save DC with disadvantage. On a success, they take 12d12 bludgeoning damage which cannot be resisted and ignores immunity. On a failure, the target takes the same damage and becomes paralysed permanently.

This paralysis cannot be undone by any type of magic, due to the infinite nature of the attack. While they are paralysed, all the individual cells of their body spin independently and cause them to be unable to move. On each round that they are affected by the spin, they take 2 damage. If a creature is reduced to 0 hit points by the initial attack, the constant damage, or in any way while their body still spins, their body scatters into dust and they cannot be revived by anything other than a True Resurrection spell.

Bonus Action:

Spatial Wormhole: You can teleport yourself and Tusk into a space you can see up to 180 feet away from you by spending 1 ki points. If you teleport to a space occupied by a creature, the creature takes 4d6 plus your Wisdom Modifier in force damage.