A couple of weeks out from the end of this and I just don't see the argument for Santo being better than either Casas or Satanico. I'm not even sure if I understand it (Will's autograph notwithstanding).
One thing I'd be curious would be if anyone who's relatively new to lucha, over the last few years, even if a lot has been seen, would put Santo other either of them. Santo's an awesome middle ground between grace and righteous violence. He portrays the image of fighting out of a Gory special, for instance, that struggle, better than anyone in wrestling history; it's a triumphant moment when he sits up and with very few wrestlers can you use the word "triumphant" with in a non-ironic way. I think he can garner sympathy extremely well, and do a lot of other things competently. He's in my top twenty, but I don't see him as close to either Satanico or Casas. I guess he's slightly more primal while they are both definitely more rounded, but it's not like they're not primal as well. Satanico is the best bad guy in wrestling history, just spewing over the top malevolent glee and Casas is a god damn trickster god. If Satanico is Mephistopheles, then Casas is either Puck or Old Stick depending on what era of his career you're looking at, and both of them are just awesome when the crowd is behind them.
I don't think I'm going to have Santo over Rey, even. He's more dynamic but 2000s Rey has that same sort of connection with the crowd with so much more creativity in match layout and we have the footage to see that on a weekly basis.
Like I said, still top 20, but sometimes I wonder if you sort of had to be there with Santo.