>>8589451He's actually very unhappy to be working with the Red Skull, it's a plot point for the "Acts of Vengeance" story.
All the villains team up and swap heroes, the goal being to present new unique threats to heroes that have grown accustomed to facing the same threat over and over again. You end up with battles like The Mandarin vs X-Men, Spider-Man vs Magneto, Mole Man vs Avengers West Coast, Thor vs Juggernaut, Dr Doom vs Punisher, Klaw vs Iron Man, Tiger Shark vs Wolverine, etc.
All the while Magneto and Red Skull are at each other's throats.
