Well, they both gain meter like crazy, and do good damage, so you’ll probably need a third who can 1.give Nemesis and Tron a good approach assist, beam is usually the standard here 2.Someone to abuse the gained meter, use it like crazy 3.Good anchor, with two hard-to-get-in characters like Nemesis and Tron, you want someone thoroughly terrifying on their own for backup.
Ideas: Doom (not the greatest anchor, but good enough, and has CHEAP assists, missiles or plasma), Strider, (Tron can convert off the assist, good at fighting Trish and Modok, great anchor), Arthur (Either gimmick or legit, he’s good last, and has a good assist), Sent (drones, why not?, actually extends tron combos very well, there’s a vid on SRK frontpage a while back about it, and he can burn meter for extra damage), Hawkeye (arrows, yeah, burns meter for extra safety), there’s probably more, but I’m forgetting a big amount of the cast right now, sorry.
Also, fun stuff, Tron’s servbot capture forces the opponent to fall down in a neutral state, always. So you can raw tag during the stun, and have them reset into someone else’s air command grab, and basically make an unescapable reset on a lot of the cast. So yeah, recall that Nemesis has one of those command grab thingies, that’s fun times right there. If you have ways to abuse the gimmick, the pairing is fantastic. I’m not so sure about gustaff fire, though. I like boulder assist, but fire does have that nice crossover counter.
There’s definitely a way to make that team snazzy, but prepare to put in a lot more effort than people using autopilot Zero teams, and other fun toptier sillyness. You run two big guys who will be hard pressed to escape either tridashers or bullet hells.