Come to think of it, Ultron did start spreading a techno-organic virus with his code in it that could convert organic lifeforms into Ultron Sentries,...
Quicksilver and ( especially ) Scarlet Witch. I'm convinced that Stan got Jack on the phone on a Friday and told Jack, "Come up with some characters...
Donna Troy. Back in the day, she's had like three different origin stories, the Nu52 happened and she got yet another one. I'm not sure what her deal...