Guillain

Guillain [ɡi'lɛ̃] is an NPC in Dead Cells who provides the player with a Mutation between biomes — up to 3 total.

After choosing mutations, the player can have Guillain reset them for 1,000 gold. A second reset costs 2000, a third 4000 and fourth 8000.

Not much is known about Guillain. He sits happily next to the pile of corpses left by the Beheaded's previous attempts. His proximity to the Collector suggests he knows him or works with him.

Guillain resembles the merchants, the Blacksmith, and the Blacksmith’s apprentice. These characters have a chameleon/goblinlike appearance, seemingly the same species.

First encounter

 * "I'm really happy I found this great stinking pile of corpses!"
 * "You can't even imagine all the stuff you can find in here!"
 * "By the way, it's an odd thing to say... But you... kind of look like these guys..."
 * "Oh yeah, sorry about the smell..."
 * "In any case, it beats selling a bunch of old ju... Stuff... Yeah, stuff."
 * "Well, I'm going back to digging through the filth for some more goodies!"
 * "I'll see you again, I guess..."
 * "Errrr..."
 * "cough"
 * "cough"
 * "cough"