Hi! Heres some suggestions for different knives at different levels of Murder Mystery so theres more motivation to grind mm.
Level 20: Baseball Bat
Level 35: Karambit
Level 50: Gold Battle Axe
Level 80: KnockBack Nemo (Skywars Reference)
Level 100: A stick with a bee tied on the end of it or just a bee so when you hit someone with it its like your stinging them with the bee.