he used to be part of an adventuring party. there was an adventure with capturing/slaying a basilisk. after a lot of cat and mouse around an old castle they cornered basilisk.
the gang of course had protection from basilisks’ stare in the form of charms/magical objects like any sensible adventurers with enough g but the basilisk had managed to get blue’s protection amulet away from him long enough to hit him with their stare. it escaped in the chaos, badly hurt.
the gang (probably consisting of dream, ink, and maybe a couple others) tried to reverse it with their own amulets, but it only slowed it down. the spells were meant to prevent it working in the first place rather than repair damage.
they make a deal with the basilisk- healing potions (because somebody had looted all the healing potions in the castle) in return for a cure for blue and a promise to leave them in peace.
the two parties traded potions. her potion didn’t work entirely as intended- it was a little half-cooked since it was kind of rushed.
technically, the basilisk fulfilled her end of the bargain. blue is no longer in any danger of being turned into a statue. basilisks cant turn another of their kind to stone.