Is there anything that says that Karnon has to roll all of his power dice at once? Can he roll a portion of them (say, 3 for example) then decide if he wants to upgrade either of the last 2 to silver?
Here's what we (me and my roommate) think about an epic party:
If using FFG printed characters only -
Nanok, this is a must since in RtL he can be incredibly durible without taking up armor from other characters. Spending the resources to upgrade his power dice increases his armor, it's a buy one get one free kind of sale in the oh so important early stages of the campaign. 45XP into the campaign he's a 16/4/7/4, its hard to find copper mosters that can do enough damage to effect him.
2nd String - Karnon, Thalia
Tobin - This guys is so broken it's not even funny, give him skills to increase range and see through obstacles. He's adding 5-8 damage to each of his attacks and isn't fragile.
Laurel of Bloodwood - This is the not quite broken version of Tobin. She can really rack up the damage, but you have to be more careful with her 8 health
2nd String - Ronan of the Wild, Kirga
Landrec the Wise - Those two extra surges are pretty good at th beginning of the campaign, but towards the end when he's sporting Flame Strike he becomes the ultimate crowd controller. 2 free surges + 5 fatigue + 12 health (good for a mage) = awesome
2nd String - Mad Carthos,
If you're able to use the FFG character creator there are some interesting things to consider:
Seer (9 point version) - This kills to ability of the OL to accumulate threat. Even if this character is otherwise useless, the party has expended 25% of there abilities to destroy at least 50% of the OLs abilities
Guardian (9 point version) - By taking a "nimble" character you begin as 8, 6, 0, 1 and 3 dice in Magic, 1 skill in each catagory. Spec the character out with fatigue upgrades, and Spiritwalker is essential, and ShadowSoul a great movement mechanic. At frist the 1 speed can seem cripling, but if played carefully, by the end game you can be a 8, 12, 0, 1 character that can effectively attack 15 times a turn (2 from battle, 13 from guard order) and each attack can come from any player within 5 spaces of you. Played right, this can be very versatile character that can protect the whole party or deal serious damage to a single target.
Sorry for the long post, but this is what we've found to be the best. Part 2 will cover some other characters that don't wall into the nice, neat categories.