Aclazotz, Deepest Betrayal / Temple of the Dead The creature is a nightmare for opposing aggro players, and the first two triggered abilities are both great
It's cheap, it can give +1/+1 counters when you gain life, and it can give lifelink to a creature
People get pulled in, those outside forces go away, and then when things change, people blame the community for ruining things, or destroying the fandom, instead of blaming the disappearance of the outside forces that made the community grow in the first place
Early in Historic's life, it went through several large changes, as additions like Strixhaven: School of Mages 's Mystical Archive, the original Jumpstart , and other tabletop innovations upset existing metagames