I recently made a Skull Servant deck that pulled off defeating Gravekeepers, somehow. It also managed to defeat two /Assault Mode dragons (in the same duel) and some other things.
I'm still losing all the time against Hieratics, Dark Worlds, Lightsworns, whatever that one deck with the Infernities is, and pretty much anything that can use lots of destruction effects while swarming, really.
Fortunately, I haven't had to deal with Evilswarm Beelzebub (or whatever it was called) yet, and for some strange reason I haven't dueled against Bujins at all despite how people kept hyping it as the new Tier 1 deck for the meta or something.
I've also taken a liking to Noble Knights and look forward to Noble Knight Percival coming soon. Bothers me how they have two Lancelots and two xyz Arthurs, though.
Oh, and this is amazing: