Gem Knight

Gem knights are the bastard children born from an unholy combination of eldritch knights and rune knights. Gem Knights are a totally unique subclass which speciallize in risky plays by harvesting the unstable power hidden within gemstones to quickly dispatch foes at the risk of their own wellbeing. Their study of gemstones and their patterns them have lead them to uncover the unusual ways nature has found to manipulate magic. Being kept secret and handed down from generation to generation, this art is usually known only to either keen jewelers or heads of the jeweller business.

P.S. gemstone spell level is correlated to its value(lvl 1 spell - 50gp gem, lvl 2 - 100gp, lvl 3 - 500gp, lvl 4 - 1000gp, lvl 5 - 5000gp)

Bonus Proficienies

When you choose this archetype at 3rd level, you gain proficiency with jeweler's tools.

Gembound Weapon

At 3rd level, you learn a ritual that creates a magical bond between yourself and one weapon. You perform the ritual over the course of 1 hour, which can be done during a short rest. The weapon must be within your reach throughout the ritual, at the conclusion of which you touch the weapon and forge the bond.

Once you have bonded a weapon to yourself, you can't be disarmed of that weapon unless you are incapacitated. If it is on the same plane of existence, you can summon that weapon as a bonus action on your turn, causing it to teleport instantly to your hand.

You can have up to two bonded weapons, but can summon only one at a time with your bonus action. If you attempt to bond with a third weapon, you must break the bond with one of the other two.

You can embed gemslots into this weapon

Gem Carver

Starting at 3rd level, you can utilize the power of gems to enhance your gear. You are able to create a total of 2 gemslots in equipment of your choice. When you reach certain levels in this class, you can create additional gemslots and use new gems, as shown in the Gems Known table.

Gems Known
Fighter Level	Number of Gemslots	Gemstone Spell Level
3rd	2	1st
5th	2	2nd
7th	3	2nd
9th	3	3rd
10th	4	3rd
13th	4	4th
15th	5	4th
17th	5	5th

 

If the spells require a saving throw, the save DC is equal to 8 + your proficiency bonus + your Intelligence modifier. The spells you can cast depend on the gems embedded in the item. Abjuration type gemstones must be embedded into armor or clothing, Illusion type gemstones into jewelry and such, and Evocation gemstones into your Gembound Weapon. Gems embedded into your weapon can be activated once per turn after you take the Attack action, while gems embedded in jewelry and armor require an action, or a reaction if the spell has that casting time

Each gem can only be invoked once before needing to be recharged. You can do so by spending an hour after a long rest to make an Arcana check with advantage for each of your gems.

Trying to invoke a chargeless gem requires an Arcana check which depends on the spells level. On a successful check, the spell is cast and all subsequent Arcana checks on that gem are made with disadvantage. The disadvantages stack, as the gem gets more and more damaged with each forced invocation. On a failed check the gem explodes and deals Spell level*3d8 force damage to the caster.

Gem Spell level	Arcana DC	Maximum Gemslots Allowed
1st	14	5
2nd	17	3
3rd	20	2
4th	23	1
5th	26	1

 

Spell Name	Spell Level	Spell Type	Gemstone Used
Armor of agathys	1	Abjuration	Onyx
Burning Hands	1	Evocation	Carnelian
Color Spray	1	Illusion	Quartz
Disguise Self	1	Illusion	Moonstone
Earth Tremor	1	Evocation	Chrysoprase
Sanctuary	1	Abjuration	Sardonyx
Thunderwave	1	Evocation	Jasper
Aganazzar's Scorcher	2	Evocation	Amber
Blur	2	Illusion	Amethyst
Invisibility	2	Illusion	Jade
Protection from Poison	2	Abjuration	Chrysoberyl
Shatter	2	Evocation	Tourmaline
Dispel Magic	3	Abjuration	Alexandrite
Hypnotic Pattern	3	Illusion	Aquamarine
Lightning Bolt	3	Evocation	Blue Spinel
Remove Curse	3	Abjuration	Peridot
Death Ward	4	Abjuration	Black Opal
Fire Shield	4	Evocation	Fire Opal
Freedom of Movement	4	Abjuration	Star Ruby
Greater Invisibility	4	Illusion	Blue Sapphire
Protection from Energy	4	Abjuration	Star Sapphire
Cone of Cold	5	Evocation	Diamond
Destructive Wave	5	Evocation	Black Sapphire
Dispel Evil and Good	5	Abjuration	Ruby
Seeming	5	Illusion	Jacinth

Crystal Clear

At 7th level, you are able to keep a calm and rational mind. You gain proficiency in Inteligence saving throws

Fracture

At 10th level, you learn how to make your weapon strikes undercut a creature's resistance to your spells. When you hit a creature with a weapon attack, that creature has disadvantage on the next saving throw it makes against a spell you cast before the end of your next turn.

Gemstone Insight

At 15th level, you can forcibly invoke a gemstones power without damaging it if you succeed its Arcana check. You can do this once per gem per long rest.

Master of Gemstones

Starting at 18th level, you can invoke your gems twice per turn.