[@thewizardguy]

Time based powers are... complicated, for a lot of reasons. Anyway, let's see this:

Disregarding everything related to personality and history (who don't seem problematic, unless they actually interfere in the RP later on).

Powers:

[Designed for War]: Goes without saying. This one's ok.

[Acceleration]: Basically, the same as Ni-Mu's abilities so it's ok as long as it's kept within reasonable limits.

[Deceleration]: A slow is alright as well, as long as it's kept within reasonable limits.

[Rewind]: Self-Heal is ok as well as long as it can't be spammed with wild abandon and make him immortal.

[Skip]: Normal teleport is ok, teleporting into the future can lead to some really iffy scenarios, it's best that you avoid to deal with this.

[Preview]: This one however is all kinds of problematic. Seeing the future is such a big ball of problems that it's best to be forgotten in it's totally. He can already control his own time as well, he needs no more dodge bonus, these two abilities are redundant when applied together.

Either way, wait for [@TheWindel]'s word now.