While the X-Men have faced their share of evil mutants, mutates, dimensional entities, and other powerful enemies, they've also fought against a number of baseline humans. I'm curious who people think are the nastiest flatscans the X-Men have ever had to deal with.
Please limit this to baseline humans ONLY. No mutates or others who've been artificially enhanced IE Pierce or Sinister.
I'm going to put up two:
The first, for sheer scale, is Reverend Stryker, particularly due to his attacks against the Xavier School in Kyle and Yost's New X-Men. It takes a special kind of douchebaggery to deliberately target children, and his actions after M-Day still have an effect on both the X-Men AND readers, to the point that news the Purifiers would be returning in a big way in the forthcoming Generation X was met with criticism over the lack of the New X-Men in the book's cast.
I also float Zander Rice from Innocence Lost for being just plain personally reprehensible, despite not appearing outside the first two X-23 miniseries. Not only do we have all the things he did to X-23, but he also fathers a child with his boss's wife, (and it should be noted Sutter practically RAISED him) manipulated said boss into giving him total control over the project, and when his wife wanted to confess to the affair, conspires to have her, his boss, and HIS OWN SON murdered to silence her. To say nothing of selling X's services to the likes of Red Skull and Kingpin. Even worse, Rice doesn't have an excuse for any of this, aside from the flimsy justification that he's punishing X-23 for Logan killing his father. He's just a sadistic and manipulative sociopath.