Aragon Greenbloom, Cursed Archdruid

Undying. If slain, Aragon's spirit refuses to stop living and insists it stays in the Haunted Forest. Aragon's body will regrow from the mud in the Haunted Forest after 1d100 days. 

Spellcasting. The archdruid is a 20th-level spellcaster that uses Wisdom as her spellcasting ability (spell save DC 22; +14 to hit with spell attacks). The archdruid has the following spells prepared from the druid’s spell list:

Cantrips (at will): druidcraft, produce flame, shillelagh

1st level (4 slots): entangle, longstrider, speak with animals, thunderwave

2nd level (3 slots): animal messenger, barkskin

3rd level (3 slots): call lightning, daylight, dispel magic, meld into stone, plant growth, protection from energy, water breathing

4th level (3 slots): blight, confusion, freedom of movement, giant insect, hallucinatory terrain, ice storm, polymorph, stone shape

5th level (3 slots): commune with nature, geas, greater restoration, insect plague, mass cure wounds, reincarnate, scrying, tree stride

6th level (2 slots): conjure fey, find the path, [spell/]heal[/spell], move earth, sunbeam, transport via plants, wall of thorns

7th level (2 slots): fire storm, regenerate

8th level (2 slots): earthquake, Tsunami

9th level (5 slots): Shapechange, True Resurrection, storm of vengeance

Quarterstaff. Melee Weapon Attack: +2 to hit (+4 to hit with shillelagh), reach 5 ft., one target. Hit: 3 (1d6) bludgeoning damage, 4 (1d8) bludgeoning damage if wielded with two hands, or 6 (1d8 + 2) bludgeoning damage with shillelagh.

Legendary Resistance (3/Day). If Aragon fails a saving throw, he can choose to succeed it instead. 

Mythic Resistance (1/Day). Aragon can become resistance to all damage for 1 minute at will.