During each players end step, if a card left your graveyard this turn, Gau deals damage equal to its power to each opponent
The more instants, sorcerys, discard and sac effects you have the better Witness is but I mostly consider it filler
Both Midnight Hunt and its partner set Innistrad: Crimson Vow would both go on to be reprinted in a set together named Innistrad: Double Feature which combined both sets into one, making the original prints of the sets alot less desired
Lim-Dl's Vault is a super-tutor
The ability that defines Regal Bunnicorn's power and toughness functions in all zones, not just the battlefield
The main purpose I could see for this commander is in a Krark deck, but in that case, itd be an inclusion, not the commander