Perception, Insight, Persuasion.
Spellcasting. The Don casts one of the following spells, requiring no Material components and using Wisdom as the spellcasting ability (spell save DC 16, +8 to hit with spell attacks):
Misty Step, Witch bolt, Arms of Hadar
Slow, Synaptic Static
Ice Storm, Mass Healing Word, Counterspell
Lighting bolt, Banishment, Web
Interface. Don Bomble rolls a D4 and summons that many Magidrones. He may summon one less Magidrone to cast banishment as part of the same action.
Starry Form. As a Bonus Action, Don Bomble channels the wild magic of the cosmos, taking on a starry form. In this form, his body becomes luminous, his joints glimmer like stars and glowing lines connect them as on a star chart. He sheds Bright Light in a 10-foot radius and Dim Light for an additional 10 feet. He can maintain this form for 10 minutes, and it ends early if he is Incapacitated or all his Constellations are broken.
Constellations. The Don's Starry Form also creates three constellations that float in the air 60 feet above him. They are forged from starry crystals reminiscent of stained glass. They have an AC of 13, a Damage Threshold of 8 and hit points of 30. If no Constellations remain, his Starry Form ends and he is Stunned for 1 turn.
Dragon. A constellation of a wise dragon appears in the sky above the Don. While this constellation persists, anytime he makes an Intelligence/Wisdom check, or a Constitution saving throw to maintain Concentration, he can treat a roll of 9 or lower on the d20 as a 10.
Archer. A constellation of an archer appears in the sky above the Don. When the Don activates Starry Form and as a bonus action while this constellation persists, the Don can make a ranged spell attack, hurling a luminous arrow that targets one creature within 60 feet of him. On a hit, the attack deals 2d8 + 5 radiant damage.
Chalice. A constellation of a life-giving goblet appears in the sky above the Don. While the constellation persists, anytime he casts a spell that restores hit points to another creature, the Don restores 2d8 + 5 hit points.
Weal. Whenever a creature the Don can see within 30 feet of him is about to make a D20 Test, he can take a Reaction to roll 1d6 and add the number rolled to the total.
Woe. Whenever a creature the Don can see within 30 feet of him is about to make a D20 Test, he can take a Reaction to roll 1d6 and subtract the number rolled from the total.
The House Always Wins (1 per day). Using this legendary action will automatically trigger 00 on The Wheel Of Automaton Autonomy instead of rolling.
The Wheel of Automaton Autonomy. As a lair action, The Don takes a spin on The Wheel of Automaton Autonomy.