Though Iron Man 3 is still a long ways off, a new casting revelation seemingly cements the long-running rumor that the film will be based primarily on 2005′s “Extremis,” a tale written by comic book scribe, futurist and all-around beloved raconteur Warren Ellis.

The story, for those of you who don’t religiously follow the exploits of charming industrialist Tony Stark, offers a new, somewhat revised origin for Marvel Comics’ favorite boozehound. Essentially, geneticists working for the US government, in an attempt to duplicate the super soldier serum that gave Captain America has Hitler-punching abilities, create an experimental “robotic microsurgery” drug that allows the human body to be reprogrammed. It allows normal people to turn into superhumans, and in the case of Extremis, it gives Tony Stark the ability to interface with a new version of the iconic Iron Man armor — necessary for Stark’s efforts to end the rampage of a similarly Extremis-boosted villain created specifically for the story.

According to Variety, Pearce is slated to play Aldrich Killian, the lead scientist responsible for the Extremis drug. Though we’ve yet to see official confirmation on the plot for the film — it’s slated to hit theaters in May 2013, so such ambiguity isn’t entirely shocking at the moment — Pearce’s involvement heavily suggests that the movie will be largely based on Ellis’ storyline, though it does make the recent news that Ben Kingsley is in talks with the filmmakers to play a villain a bit more confusing.

Though initial speculation had Kingsley pegged as playing Iron Man archenemy (and wildly racist “yellow menace” stereotype) The Mandarin, Variety claims that Iron Man 3 insiders have denied this idea. Pearce’s involvement and the presumed focus on Ellis’ Extremis storyline does little to clarify what role Kingsley might instead be playing, though, regardless, the inclusion of the talented Oscar/BAFTA/SAG and Golden Globe winner can only mean good things for the upcoming sequel.

With Mandarin off the table, we’ve got our collective fingers crossed that Kingsley will be playing the time-hopping walking paradox alternately known as Immortus and/or Kang The Conquerer. If there’s one thing the series has been lacking to date it’s an endless stream of confusing temporal paradoxes and opportunities for Robert Downey Jr. to engage in witty banter with a displaced, chronologically-confused version of himself.