With how big libraries are in Commander, you are going to need the extra help, and Bruvac helps get your opponents to zero cards much quicker
They add a card that shuts down their own plan, then decide graveyard hate is bad. If you rely on your own graveyard (reanimator, aristocrats, delve, flashback, recursion commanders), prioritize: Targeted exile effects (pick off key threats) One-shot nukes that you can time (hit them, then keep playing) Effects that do not blanket-exile everything forever If you do not use your graveyard much, you can play the heavier continuous pieces with fewer downsides
Treat them as such
Not only is it good to drop in off of Aether Vial like all the other creatures, but being a legendary creature is actually a big advantage: The deck can continually reuse it thanks to Karakas
I love everything about the design of these partners from both flavor and function perspective
This counters all spells or abilities on the stack no matter how many