Tome of UWU is a post-Skeletron Spell tome that is dropped from the Slime's Last Hope boss fight.
It will cast one green orb that after a certain distance, will split into 5 more orbs in the shape of a star, that will disappear after a certain distance.
The main orb will split prematurely if it hits a enemy.
Both the main orb and the splitting orbs go through tiles, so it is a good weapon to use in cramped spaces.
the main orb does not produce light, but the splitting orbs do, so it can be used in cave exploring