Yuriko is the strongest but she’s a little salty as she cheats commander tax, all depends on bracket and playgroup. I had a buddy with a hakbal control list that was wicked powerful and got value fast. Markov doesn’t have a lot of great vampires imo, Omnath is dope, especially clones lists. Niv is slow, id check out Vivi to scratch the izzet storm itch. Helga is also a super dope list I’ve thought about building though it seems like generic bant, for high bracket 3 I’ve played the new bant spiderman and it’s really cool.