Ki. The force that flows through all living creatures. Monks use this energy to enhance their strengths, debilitate their foes and perform feats any other would deem nothing short of miraculous.

However, the body has to be sparing in how it distributes Ki, lest it overtakes the body and destroys it from within. Luckily, the body regulates this on its own through certain nodes in the body that open and close instinctively to allow ki to flow to where it is needed. 

Form of the eight gates

As a bonus action on your turn, you can spend at least 1 ki point in order to activate the form of the eight gates. When you do so, you gain each opened gate's benefits for the form's duration.

When you use this bonus action, you open a number of gates equal to the number of ki points spent. Your gates open consecutively, always starting with the first gate. Additional gates can be opened on your subsequent turns by spending additional ki points, with each additional ki point spent opening another gate, up to the highest gate you are capable of opening. transformation last for 1 minute, until you are reduced to 0 HP or choose to end it as a bonus action. 

At 3rd level, you are able to open the first and second gates. You will suffer the drawbacks when the form ends. You must make a constitution saving throw, DC 10+ the number of gates you had open for the duration. 

1st Gate of Opening: You spend 1 ki point to open the gate of opening, removing your mind's restraints on your muscle strength and speed. While this gate is active, you gain advantage on strength based ability checks and saving throws, and your movement speed increases by 5 feet.

2nd Gate of Healing: You spend 2 ki points to open the gate of healing, sending waves of adrenaline all throughout your body while allowing your ki to mend your body. Upon activation, your regain hit points equal to your monk level, while also giving you temporary HP equal to half your monk level. These temp HP only last when the gate of healing is active and disappear once the effect ends. In addition you also gain advantage on constitution saving throws. 

Whirlwind Strike

At 6th level, Once per attack when you roll a 1 or 2 for damage with your unarmed strikes or monk weapons, you can re-roll the die, using either total. 

3rd Gate of life

You spend 3 ki points to open the gate of life. While this gate is active, you regain a number of hit points equal to your Constitution modifier at the start of your turn if you have no more than half of your hit points left. You don't gain this benefit if you have 0 HP. 

4th Gate of Pain

You spend 4 ki points to open the gate of pain. While active, you gain an additional 1d4 to attack and damage rolls. When the effects of the gate end, you're overwhelmed by a wave of stress, causing you to take damage equal to half your monk level. This last feature applies to the 5th, 6th, and 7th gates as well. 

Instant Opening

Starting at 11th level, your first two gates cost no ki points to open and you do not suffer the lethargy drawback if you fail your drawback saving throw.

Also, you can now open your gates as a free action on your turn, no longer requiring a bonus action to do so, though you can still do so only once per turn. 

5th Gate of Limit

You spend 5 ki points to open the Gate of limit. While active, your movement increases by additional 5 feet (total of 10 feet) and you gain an additional 1d6 to attack and damage rolls. In additional, you can use your patient defense and step of the wind features without expending ki points.  

6th Gate of View

You spend 6 ki points to open the gate of view. While active, you gain a aura of ki in a 5 foot radius. Whenever a creature starts their turn , moves within range of or makes a melee against you while in the aura, they must make a Dex saving throw. On a failed save, the ki energy lashes at them, causing them to take force damage equal to 1d6 + your wisdom modifier. In addition, when you use the attack action on your turn, you can spend 1 ki point to increase the range of your unarmed strikes by 10 feet, as tendrils of ki stretch out of your fists and feet. This attack deals force damage instead of bludgeoning damage, and you deal an additional 1d10 force on top of that. 

Master of the Eight Gates

When you reach 17th level, your first four gates cost no ki points to open.

Additionally, whenever you score a critical hit with an unarmed attack or monk weapon, you regain 1 ki point. 

7th Gate of Wonder

You spend 7 ki points to open the Gate of Wonder. While this gate is active, you gain resistance to bludgeoning, piercing and slashing damage from non-magical weapons, and your movement speed increases by additional 10 feet (total of 20 feet) 

8th Gate of Death

You spend 8 ki points to open the Gate of Death. Once activated you gain the effects of all previous gates, while also gaining the following effects:

Your Strength and Dexterity scores increase to 30.

Your jump distance is tripled.

Your unarmed strikes deal additional force damage equal to half your monk level.

You can use flurry of blows feature without expanding ki points.

You cannot be charmed or frightened.

You are immune to bludgeoning, piercing and slashing from non-magical weapons.

If you are reduced to 0 hit points while the gate of death is still active, you do not fall unconscious. When your negative hit points are greater than or equal to your maximum hit point total, you die immediately.

When the gate closes, you take damage equal to twice your monk level. If this damage reduces you to 0 hit points or you have 0 hit points or less when the gate closes, you die immediately and can only be revived through true resurrection or a wish spell.