Curse of Yondalla

When you cast this spell, choose a target creature you can see within range.  That creature will be affected based on its creature type or origin:

Undead: Unless the undead is a divine being (god, demi-god, etc), they must make a Wisdom Saving Throw or be utterly destroyed. If they succeed the saving throw, they will still take 8d8 Radiant damage.  If this damage reduces the undead to 0 hit points, they are utterly destroyed.  This spell effect ignores all Reincarnation or Regeneration abilities.  Undead, while destroyed, can be recreated by the usual spells (Animate Dead, Create Undead, etc).

Extraplanar: If a creature is from another plane (celestial, fiend, elemental, etc), they must make a Wisdom Saving throw or be banished to their original home plane for 100 years. If they succeed the saving throw, they will still take 8d8 Force damage from the attempted shunting. The extraplanar being cannot return early unless they have a Wish spell cast.

Material: If a creature is from the current plane, they must make a Wisdom Saving throw or be stunned for one minute. They can attempt the saving throw again at the end of each of their turns, ending the effect upon a success. For every failure, roll a die in a specific order to reduce the target's age by the amount. The die used in order are 1d8, 1d10, 1d12, 1d20, and then 1d100 for each additional turn. If the target reaches infancy before the minute is over, the spell ends before they cease to exist. The infant will lose all class levels and abilities and will grow at a normal rate. If the target succeeds but has had its age reduced by the spell, that reduction remains in place. The only way to reverse the effects of the spell is with a Wish spell or Remove Curse cast at 8th level or higher.

 At Higher Levels: If you cast this at higher levels, you can target one additional creature per spell level.