Anybody? Ok...so, this was something I kinda wanted to do for a while, though without knowing exactly how. I've been running a combo deck for some time now, and honestly, I really just in general like the aspect of special combos even if many of them aren't quite so practical as others. I'll focus on the ones that actually are useful and can help you to be more competitive. Sometimes it gives you a good starting point to build around, and sometimes it also just keeps some decks a little more fresh in my opinion, because I think wall decks are about the lamest thing anywhere and refuse to have more than 1 of the same card in either of my decks. :P
Since this will be a work in progress, it'll probably look butt ugly for a while. Sorry about that. XD (this'll probably be a hub from which I link a page for each combo now that I'm looking at this mess...)
Tactics[]
Great Brains - Mr. Fantastic, Iron Man, Dr. Strange = 7% ATK improvement on deck.
Mutant Masterminds - Magneto, Emma Frost, Scarlet Witch = 6% ATK improvement on team.
Speed[]
Cracking Wise - Spider-Man, Deadpool, Rocket Raccoon, Ghost Rider = 7% ATK improvement on Speed.
Hey Rocky - Spider-Man, Rocket Raccoon = 5% ATK improvement on Speed.
Ogre, Devil, Spider - Blade, Ghost Rider, Spider-Man = 7% ATK improvement on Speed.
Bruiser[]
Homo Superior - Apocalypse, Jean Grey, Cyclops, Wolverine = 7% ATK improvement on Bruisers.
X-Power - Wolverine, Jean Grey, Cyclops = 6% ATK improvement of heroes.
Unlimited Power - Hulk, She-Hulk, The Thing = 10% ATK improvement on Bruisers.
Gamma Brothers - Hulk, A-Bomb = 5% DEF improvement on Bruisers.