I don't think Hawke would be the main villain. He isn't ruthless enough - I like that he helped out the allies in DS though. If he does come back, I think it'll be on the good side, but only because it's benefitting him.
Then again, Kindle(US)/Candy(EU) is far from Leader material.
Neither was Von Bolt really. Sturm was only the real terror I found - I mean, movement cost 1 over all terrain is pretty menacing.
ooh, Maybe a Von Bolt/Sturm tag alliance?
and maybe a half-tag option, where you can tag with 1power+1SPower, but on the second turn, only non-infantary/transport units can attack, and the attacks are weaker.
and maybe a tag option where you can either have standard tag power, (2 turns, 2 super COs), or a super combined tag power (1 turn, both Super COs simultaneously+ their own abilities combined). That'd be awesome, but crafty, because for example:
Koal(US)/Zak(EU) and Adder - Movement range increases by 4 - not as good as the standard tag...
but
Hachi and Colin - Costs will be reduced like mad - much better than standard tag
The possibilities are endless