Yhendorn Genrona the Purple

Diamond Skin. Yhendom, is a man made entirely out of amethyst gems. For a maximum of 3 times every long rest, he can reinforce his body with more crystals, giving him a +7 to AC until the start of his next turn. He can do this as a bonus action.

Graced Within Darkness: While in Darkness, Yhendom can recover 1d4 hp at the start of his turn. This can stack with other hp boosts.

Spellcasting. The [Yhendom] is a 9th-level spellcaster. Its spellcasting ability is [INT] (spell save DC 19, +13 to hit with spell attacks). The [Yhendom] has following [10] spells prepared:
Cantrips (at will): [Sword Burst], [Sapping Sting] 
1st level (4 slots): [Catapult], [Cause Fear] 

2nd level (4 slots): [Aganazzar's Scorcher], [Dragon's Breath]

3rd level (4 slots): [Antagonize], [Blink], [Counterspell]

4th level (2 slots): [Banishment], [Elemental Bane]

5th level (2 slots): [Transmute Rock], [Mislead]

9th level (3 slots): [Time Stop], [True Polymorph], [Prismatic Wall]

Splintered Amethyst (Costs 1 Action). Any creature damaged by Yhendom's melee attack, can be cursed by Yhendom's gem splintering. Creature must succeed a DC 22 CON save, otherwise they will be cursed. The curse is as follows:

Yhendom's Gem Splintering is a progressive curse. At the end of each turn, if the curse is not dispelled, it will progress to the next stage. It starts at the first stage immediately on the fail.

- Yhendom's influence creeps into the creature's mind, they can be turned away from one of their actions before they can finish the action, this can be done once a turn.

- Yhendom's gem will begin to sap at the energy of the creature, the creature will suffer one level of exhaustion.

- Yhendom's gem will act as a poison, any STR or CON related checks will be rolled at disadvantage for the affected creature. 

- Yhendom's gem will weigh down the creature, causing them to have half their movement speed as default.

- Yhendom's gem poison will begin to attack the heart of the creature, all rolls will be at disadvantage for the affected creature.

- Yhendom's gem will surround the heart, causing them to immediately drop to 1hp. 

- Yhendom's gem will puncture the heart, causing them to fall unconscious.

Ruptured Ground. The ground ruptures underneath Yhendom as an action. All creatures within 200ft must make a DC 19 DEX saving throw, besides Yhendom. If failed, a creature takes 4d10 magical piercing damage, they move within the range as if it was difficult terrain. If successful, creature takes half the damage and can walk across the ground as normal. This can be done once a day. Yhendom can recover 1d4 hp at the start of his turn while Ruptured Ground is in effect. Ruptured Ground can be dispelled or destroyed with enough physical force.

Piercing Crystals. Melee Weapon Attack: +15 to hit, reach 5 ft., 1 target. Hit: 17 (2d10 + 7) [magical piercing] damage. 

Amethyst Summon. Yhendom can turn a shard of Amethyst into an Amethy-ling, if Ruptured Ground is in effect, once, as a bonus action.

Amethyst Bond. Any other creature made out of the same materials that Yhendom is, Yhendom can force to move a total of half of the creature's movement speed as a reaction. This cannot trigger an attack of opportunity. 

Amethyst Burst (Costs 1 Action): Yhendorn calls forth a portion of his ruptured ground to explode in a 10ft radius. All creatures within the radius take 4d12 thunder damage. All creatures within the radius must make a DEX saving throw of a DC 17, upon success they will only take half damage.