Oh, this gets annoying REAL fast, so bear with me.
Wanda went to Doom to get his assistance in bringing back her children from Mephisto. His attempts to aid her (and, of course, gain cosmic power for himself... he is Dr. Doom, after all.) caused her to bond to a strange cosmic entity, which for simplicity's sake is referred to as the Life Entity, although it's begging for a retcon. That entity has manipulated many of Wanda's decisions and actions during Disassembled. Doom has also taken credit for manipulating Wanda as well to destroy the Avengers. So, yeah, Hal Jordan/Jean Grey at BEST, with some mind control on top of that! We're still unsure as to whether or not Agatha was ever returned to life or not, same as Wonder Man, actually.
The Magneto/Cap thing... we've had multiple interpretations of that, actually. For one, it's worth mentioning that the UN gave Magneto a country well and truly after Fatal Attractions, so he wasn't wanted again until Planet X, surprisingly. And then things get way worse. We've heard from an alternate reality Dr. Strange that Cap was actually actively collaborating with Wanda as well and it was his knowledge of strategy that helped her to really see how to destroy the Avengers, only snapping out of it when he was challenged to rebuild the Avengers. Whether this is because of Wanda's mental manipulations as seen in Captain America and the Falcon at the time or because Cap lost his mind is open to interpretation... as is whether or not Strange's vision is as true of our reality as well as his own. So, ultimately, who knows?