Immutable Form

Ydrogeus is immune to any spell or effect that would alter its form.

Sphere of the Limit

A glowing sphere embedded in Ydrogeus’s chest constantly shifts in color.

As a bonus action, Ydrogeus rolls 1d4 to determine the sphere’s color:

1 – Red
2 – Green
3 – Blue
4 – White

The sphere remains in that state until changed again.

Red Sphere — Sphere of Execution

Ydrogeus’s melee attacks deal an extra 1d20 slashing damage.

Green Sphere — Sphere of Restoration

At the start of its turn, Ydrogeus regains 1d20 hit points.

Blue Sphere — Sphere of Adaptation

• Ydrogeus has advantage on all saving throws.

• Whenever it takes damage, reduce that damage by 1d6.

• Each time it takes the same damage type again, the reduction increases by +1d6 (stacking).

• If the total reduction exceeds the damage taken, Ydrogeus regains the excess as hit points.
  
  

  White Sphere — Sphere of Reflection

  When a magical attack hits Ydrogeus (after beating its AC), roll 1d20:

  If the result is 20 or higher, the spell or magical attack is reflected back at the attacker, using the original attack roll or save DC.

  On a lower result, the attack resolves normally.

Limit Cleaver

Melee Weapon Attack: +13 to hit, reach 10 ft., one target.
Hit: 3d12 + 7 slashing damage.

As a bonus action, Ydrogeus rolls 1d4 to determine the sphere’s color, if he wishes so.

Ydrogeus can take 3 legendary actions, choosing from the options below. Only one legendary action can be used at a time and only at the end of another creature’s turn. Ydrogeus regains spent legendary actions at the start of its turn.

Step of the Limit (1 Action)

Ydrogeus moves up to 20 feet without provoking opportunity attacks.

Sphere Surge (1 Action)

Enhances the current sphere until the start of Ydrogeus’s next turn:

• Red: +1d10 additional slashing damage.

• Green: Regains an extra 1d10 HP.

• Blue: Damage reduction increases by an additional +1d6.

• White: next roll with advantage to reflect.

Cleaving Judgment (2 Actions)

Ydrogeus makes one Limit Cleaver attack.