[Lumen]

There are no theory that super speed allows you to reverse or control time. Time flows, in theory you could revert time by changing the flow of time, which is diverted into light and atoms. Something that has nothing to do with speed. Speed alone cannot alter time, unless you refer to the terrible thing of Superman's; flying around the earth to reverse time thing. Which by the way, wouldn't work. I also stated that in a fight, Immorality would be far more useful than Super Speed.

No one really knows how time travel works, so thats irrelevant I guess but thats beside the point.
Personally, I'd want super speed. Yes, I've watched a tonne of Flash recently, almost caught up and it's getting pretty damn good but he's always been one of my favourites heros. Long before the TV series! That's just what I would choose, I'm sure people can beat me if I had that power but thats a risk I'd be willing to take.

So what would you choose if you could choose only one?

Well why would an immortal guy wanna fight someone with super speed in the first place, would take him forever and the speedster would just give up and leave him on his lonesome :p

Fight reason could be a simple as; Immortal guy was going to kill speedy guy's loved ones. (Classic comics.) If that was the scenario then the immortal would have won. Simply because, he could just stand there until speedy got tired. Woops, dead, lost. Woops. I also did state what power I'd like. (Before you even.) I stated; The ability to alter existence itself. As that power pretty much includes every power you can possibly imagine.