Citadel Warden

Servant of the Citadel. The warden can navigate the halls of the Wandering Citadel perfectly and can recall any path it has traveled.

Burden of Aeons. Other creatures have disadvantage on saving throws while within 10 feet of the warden.

Unnatural Nature. The warden doesn’t require air, food, drink, or sleep to survive.

Innate Spellcasting. The warden's innate spellcasting ability is Intelligence (spell save DC 19, +11 to hit with spell attacks). The warden can innately cast the following spells, requiring no material components:

At will: command (at 5th-level), detect magic, catapult (at 5th-level), passwall, wall of stone (does not require concentration), meld into stone

3/day each: telekinesis, temporal shunt, gravity sinkhole

1/day each: modify memory, scrying (as an action)

Multiattack. The warden can make three attacks. Alternatively, it can use its Gaze of Eternity (if available) and cast one spell from its Innate Spellcasting.

Claw. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 6) slashing damage + 7 (2d6) force damage.

Temporal Bolt. Ranged Spell Attack: +11 to hit, range 60 ft., one target. Hit: 13 (3d6 + 6) force damage and the target's speed is reduced by 10 feet until the beginning of the warden's next turn.

Gaze of Eternity (Recharge 5-6). The warden unleashes a beam of temporal energy from its eye in a line that is 5 feet wide and 300 feet long. Each creature in that area must make a DC 19 Dexterity saving throw. On a failed save, a creature takes 43 (10d8) force damage and has its speed reduced to 0 until the beginning of the warden's next turn. On a successful save, a creature takes half damage and suffers no other effects. A creature that is reduced to 0 hit points by this spell is instantly petrified instead of being killed.

Anomalous Presence. Whenever a creature targets the warden with a ranged attack, the warden can use its reaction to teleport to within 5 feet of the attacker and make a Claw attack against it.