I had some ideas for additional mobs the transformation powder can effect. Take or leave them at your leisure:

• Carminite Ghastguard <=> Ghast
• Towerwood Borer <=> Silverfish
• Carminine Golem <=> Iron Golem
• • Being able to turn the golems into power allies so easily may make parts of the dark tower too easy.
• Maze Slime <=> Slime
• Twilight Wraith <=> Vex
• • Wraith behaves similarly to the vex, and both are ghosts. More fitting than the blaze.
    Stable / Unstable Ice Core <=> Blaze
• • Blaze is more similar to these than the wraith.
• Upper Goblin Knight <=> Pillager
• Lower Goblin Knight <=> Vindicator
• Block and Chain Goblin <=> Evoker
• • Since the redcap goblin turns into a villager, I figure the more militaristic goblins can turn into illagers.

I like the Ghast, Borer, Maze Slime, and Wraith ones, but I don’t agree with the rest

The philosophy is that not every mob has to have an analogue to a Vanilla mob