Good luck!
Yeah, I see now. Breaking the guard to let the second strike from Split get more damage in. Which is good against Thunder Immune things since you can't use Block Buster to replace Guard Break in that case.
Tons of things to think about if I were a heavy Mixer / Potion thrower. *Do I Bust the Block or Break the Block... Decisions, decisions* (ᗒ ᗨᗕ)