I think it could probably do with clarification style errata!
The power duration in its "stat block" says "1 round per level or until discharged". This makes it sound like it can be used once but you can delay the time at which it is used for up to your level in rounds.
Compare it with the 7th level power "fate of one", which for 13pp lets you reroll one thing as an immediate action.
If it *does* allow you to take one reroll each round it looks significantly better than the 6th level Greater Precognition that gives you a single +4 bonus at some point in the next (level) hours!
Although having to make a saving throw yourself doesn't come up very often on your own turn, the ability would end up looking like this:
Manifest Second Chance
For the next 9 melee rounds get two chances to hit with your primary attack each round ?!? I can imagine 12th level wilders or 18th level psywars rushing to get this via "Expanded Knowledge" if that is the case
Cheers