Mersenne

Medium celestial [divinity], Neutral Good

Armor Class 40 (Natural armor)

Hit Points 2,300

Speed 80 ft.

STR 25 (+7) DEX 30 (+10) CON 30 (+10)
INT 30 (+10) WIS 26 (+8) CHA 27 (+8)

Saving Throws Con +20, Int +20, Cha +18, Proficiency Bonus +10

Skills All with Expertise

Damage Resistances All; Bludgeoning, Piercing, and Slashing damage from magical weapons

Damage Immunities Bludgeoning, Piercing, and Slashing damage from nonmagical weapons

Condition Immunities Exhaustion, Paralyzed, Poisoned, Stunned

Senses Truesight 480 ft., Passive Perception 38

Languages Understands all languages

Challenge 49 (1,210,000 XP)

Controller of Luck. Mersenne can straight-up cheat at D&D since he controls luck.

Magic Immunity. Mersenne cannot be affected by any spell unless he either chooses to be.

Magic Weapons. Mersenne’s weapon attacks are counted as magical.

Unusual Nature. Mersenne does not require food, drink, air, or sleep.

Innate Spellcasting. Mersenne’s innate spellcasting ability is Intelligence (spell save DC 31, +22 to hit with spell attacks). Mersenne can innately cast the following spells, requiring no material or verbal components:

Cantrips: Friends, Guidance, Light, Mage Hand, Prestidigitation, Shocking Grasp

1st level: Chromatic Orb, Magic Missile, Sanctuary, Sleep

2nd level: Alter Self, Arcane Lock, Detect Thoughts, Enhance Ability, Hold Person, Knock, Rope Trick, Suggestion

3rd level: Counterspell, Dispel Magic, Fireball, Haste, Major Image, Remove Curse, Revivify

4th level: Banishment, Death Ward, Dimension Door, Freedom of Movement, Polymorph

5th level: Awaken, Mislead

6th level: Forbiddance, Mass Suggestion, Otto’s Irresistible Dance

7th level: Plane Shift, Resurrection, Teleport

8th level: Control Weather, Demiplane, Mighty Fortress, Power Word: Stun

9th level: Astral Projection, Foresight, Gate, Invulnerability, Time Stop, True Polymorph, True Resurrection, Wish

Actions

Multiattack. Mersenne makes two melee attacks with his walking stick.

Walking Stick. Melee Weapon Attack: +20 to hit, range 5 ft., one target. Hit: 1d10+10 bludgeoning damage plus 2d6+10 Force damage, and the target must succeed on a DC 30 Charisma saving throw or become Stunned for 1 minute. An affected creature can repeat this saving throw at the end of each of their turns, ending the effect on itself on a success.

Legendary Actions

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

Walking Stick. Mersenne makes a walking stick attack.

Spell (Costs 2 Actions). Mersenne casts a spell that has a casting time of 1 action.