Idea 1: After failing the first time Justin Hammer (Sam Rockwell) escapes prison when an inmate known as Fred Myers who was a baseballer (Tony`s favourite player) was sent to prison after assassinating the coach (to take over the team) helped Hammer out after agreeing to build various boomerangs to destroy Iron man/ Tony Stark. Meanwhile an assassin known as Ghost is trying to make a name for himself by killing Stark who later turns out to be a former SHIELD Agent
Villains: Ghost, Boomerang, Hammer
Who should play them: Jeffery Donovan (Ghost) and Eric Bana (Boomerang)
Why this idea can work: we have seen Hammer arrested and wanting revenge.
Idea 2: While still in prison Justin Hammer is confronted by a mysterious man how is willing to build Hammer a suit (Titanium Man) for a reasonable price and Tony dead. Hammer accepts and is defeated by Tony.
Villains: Titanium man (Justin Hammer)
Who should play them: Sam Rockwell
Why this idea can work: Same as last idea
Idea 3: Run away test subject of Extremis and bio weapons manufacturer, Ezekiel Stane (long lost son of Obadiah Stane) creates his own Iron man suit and vows revenge on Tony for killing his unknown dad
Villains: Iron Man 2.0
Who should play them: Leave that up to the CBMers...
As always feedback if possible