Defeat a ghost leviathan...

Successfully defeat umbrathirax

Defeat an ultra-instinct pusher (on the highest difficulty) by using a watcher's lifesteal. somehow...

Buy something from the shop.

End a level with 1000 or more plasma on you.

defeat every single enemy on a long, labyrinth or hard level.

get through a level without ever getting hit

Talk to the soul of light...

Finish a level on the hardest difficulty

Get an enemy to take 80 or more damage from a single tick of poison

Successfully defeat Vulture

Find a cursed page, bring it to the witch...

Equip 5 weapons at once!