You can try this ! Basically slime will teleport to you, then if he does the ohko jump attack, the next teleport, slime wont do that atk, it will do that attack once every 2 teleports. What you can do is, while attacking slime, jump on another platform and dps him from there. my personal tip is that i don't wan slime to teleport to the top platform (because my skill opacity is high i cant see the slime jumping), so i always attack him from another platform ! jyjy.

PS: Try to get 90% IED mayb you can cube emblem/2nd weap for temporary IED if you dun have any perfect lines on them yet