Magic Resistance. Ascenikar has advantage on saving throws against spells and other magical effects.
Adapted Corrosive Form. A creature that touches Ascenikar or hits him with a melee attack while within 5 feet of him takes 4 (1d8) acid damage. Any nonmagical weapon made of metal or wood that hits Asceinkar corrodes. After dealing damage, the weapon takes a permanent and cumulative −1 penalty to damage rolls. If its penalty drops to −5, the weapon is destroyed.
Nonmagical ammunition made of metal or wood that hits Asceinkar is destroyed after dealing damage.
Ascenikar can eat through 2-inch-thick, nonmagical wood or metal in 1 round.
Spider Climb. Ascenikar can climb difficult surfaces, including upside down on ceilings, without needing to make an ability check.
Spellcasting. Ascenikar is an 18th-level spellcaster. His spellcasting ability is Intelligence (spell save DC 17, +10 to hit with spell attacks). Ascenikar can cast disguise self and invisibility at will and has the following wizard spells prepared:
Cantrips (at will): fire bolt, light, mage hand, prestidigitation, shocking grasp
1st level (4 slots): detect magic, identify, mage armor*, magic missile
2nd level (3 slots): detect thoughts, mirror image, misty step
3rd level (3 slots): counterspell, fly, lightning bolt, Ascenikar's Implosion (fireball but half acid and force)
4th level (3 slots): banishment, fire shield, stoneskin*
5th level (3 slots): cone of cold, scrying, wall of force
6th level (1 slot): globe of invulnerability
7th level (1 slot): teleport
8th level (1 slot): mind blank*
9th level (1 slot): time stop
*The archmage casts these spells on itself before combat.
Acidic Fist. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) bludgeoning damage plus 18 (4d8) acid damage.