Ultron

Ultron. No question. Name one villainous AI who is more evil than Ultron (considering one of his variants destroyed like 25% of the multiverse; somewhere along that line).

How would AM beat Megatron and Ultron?

Isn’t AM a reality warper

In response to Unicron88, I don't think Infinity Ultron destroyed THAT much of the multiverse, since I can probably guess that with that much destruction, Miguel O'Hara would've spoke about it (He spoke about the incident in "No Way Home", so chances are he would've if Ultron did so much to the multiverse). I am going to guess that I-Ultron destroyed a good few universes, yet not enough to make considerable damage.

For my vote on this, AM. He is a sadistic reality warper, and chances are can out-do Ultron in smarts even with the Infinity Stones, hell he may even find a way to STEAL them.

AM shows no remorse, while Ultron tends to hold back just to savor the destruction (at least last I checked, not really sure, correct if wrong). For Megatron, he may get a chance to do some considerable damage, and for the other lad, I have zero clue.