Villain for Avengers 2.
I think Ultron being introduced in the second movie is a bit over the top though, he's one of those "be all end all" villains for Marvel.
Most OP version of Ultron vs most OP version of Superman
Also, most OP version of Thanos vs most OP version of Superman
Who would win in that. If needed, please make a thread XD
With non canon, we have to take into account Superman Prime One Million.
Though I guess Thanos with IG would be pretty goddamn stiff competition. I'm leaning towards Thanos a bit though.