@Jaesun
doing fire damage from whatever source you prefer to it, is sufficient.
There's some weird sort of problem, that's been reported over at kerzenburg several times now:
The Fission Slime is killed without using fire damage and it doesn't split into new slimes upon death, it simply dies.
As
SCS added the fire damage as a condition for transport to the Chess Board, there's a possible dead end here.
Tough I'm still surprised that many people don't notice the interactable statues with float over text in this level of Durlag's Tower.
10th
Avast! You cannot defeat our titan-mounted submarine staffed by cannibal vikings! - Nodwick
"I grab his deceased spirit and piledrive it back into his body, duplicating raise dead." - Psyren Oots board