Ok, first, the idea of leading into conflict in Epic levels between the Keeper of Everflow (who wants to free souls to follow their own destiny) and a Marshal of Letherna is actually kinda awsome. A battle royale final fight, not so much; the best way to handle this stuff is discussion, argumentation, etc, not a simple throwdown, but angst makes for good roleplaying -- and if the midseason baddie is Orcus, there would be reason for you to put your philisophical differences aside (for a while).
Second, I don't think a controller/striker battle is as fore-ordained as some do. Sure, a striker can just kill you if they go first -- but the controller can simply shut down the striker. Look at powers that dominate, stun, debuf attacks, or blind.
Third -- talk things over with the other player. Don't worry about what the GM is trying to do -- the most he or she can do is "rocks fall, everyone dies". Do you want to play up to a battle royale at the end? Do you want to play out an angsty story where your paths lead in different directions and the party has to decide who to follow? Do you want to play out an angsty story where your paths lead in different directions, and one of you has to turn aside from their path because friendship is more important? Do you want to stay "friends to the end" and avoid conflict?
Once you've got a better idea of where the other player is, you'll -both- have a better idea of what direction you want to take things, on a much more solid level than "I want to optimize my character so this isn't just a slaughter."
Also, protip: If you -do- go for any of the angsty options, you want to play up the friendship now. Hell, if the characters' sex/orientation is compatable, it would be fun to play out a love plot, just to add spice to the inevitable conflict later on, but even if not, having the characters become friends, rather than just battle companions would made all the angsty options far sweeter (and even some of the less angsty options).
