>>28470555M-Ray is manageable and while it has no safe counter a couple things can somewhat handle it, like defensive P-Don or the most defensive Arceuses, probably at the cost of dying as well waiting for Toxic/LO to do its job.
The only genwun thing that can match Mewtwo is another Mewtwo. It can just switch out of your Toxic and make it normal poison, and now you can't even paralyze it anymore. It has insane bulk, great attack for the time, stupid special that it can just +2/+2 to instantly, and it has the best type in the game on top of having Recover. It can switch into practically anything that isn't a STAB Hyper Beam, and even then it can just recover on the recharge turn.
M-Ray is probably the closest we've had to something that stupid, though. Easily.
