BOOM POW!

I Said I Cast Fireball. Boom will still uses attacks even if they damage him as well.

Pain Tolerance. Advantage on saving throws against being frightened or stunned. When reduced to 0 HP, the character can drop to 1 HP once per long rest

Spellcasting. The illusionist casts one of the following spells, using charisma as the spellcasting ability (spell save DC 13):

At will: programmed illusion, major image, minor illusion, polymorph

Punch. 1d4+1 bludgeoning damage

Off The Roof. Boom magically flies 20ft into the air and tries lands on on creature, the creature must succeed on a DEX 12 save or both the creature and boom take 2d6 bludgeoning damage. On a successful save, the creature dodges and boom still takes the 2d6 bludgeoning damage.

Bull Rider. Boom gets onto an invisible bull that travels 20ft in a straight line kicking in a 5ft area dealing 1d6 bludgeoning damage and knocking creatures it hits prone. 

Don't Try This At Home. Boom appears on top of a hill and rolls down it in a shopping cart. The cart tips and flings Boom 20ft towards the nearest player. The player must succeed on a DC 14 DEX save or take 1d8 bludgeoning damage. On a successful save Boom misses and still takes the 1d8 bludgeoning damage.

Outhouse Catapult. +2 to Hit, 10ft area, 2d6 bludgeoning damage. Boom disappears and falls from the sky in a used outhouse on to a random creature. Targets must succeed on a DC 17 WIS save or they sustain the Frightened condition till passing the save on a successive turn. 

Pain Killer. Boom gains 10 temporary hit points. These hit points do not stack.

Taser. +2 Hit, one target, 5ft range, 1d4 electric damage and gives the stunned condition for one round.

Not Safe For TV Audiences. Everything cuts to black as a censor symbol takes over every characters vision. After the effect passes every character has moved from their original position. players must roll a d4 to decide what else of their condition has changed.

Animal Den. mislead, conjure animals, teleport, hallucinatory terrain, misty step

Pregnancy. Party is transported to a black black void where a voice picks a player "at random" to participate in the next challenge. Selected player becomes pregnant as they and the party appear in a delivery room. Selected player's water breaks as contractions start. The player must succeed on five increasingly difficult CON saves , losing 5% hp on a fail, till the baby is born. (saves start at 10 then increase by 2 after every save passed)