I know the name Ack May turn some heads away, but there are a few gems in his archive that are worth giving a try. One of these gems happens to fit your search inquiry. Recoil is my personal favorite PS Fic, and I’ve read more than a few Fics that use time travel. Ack’s above average writing and solid grasp on character development/story structure is pretty noticeable in this one. Taylor gets sent back in time after the New Delhi Behemoth fight goes terribly wrong, by one Phir Sē. Without revealing too much, she loses her powers after getting plopped back in time, and eventually joins the PRT a la Deputy. Updates come periodically on a slow schedule, but there’s plenty already written down as of now. A fair warning, you can tell this is written by Ack. Expect some writing habits (none of the bad ones fortunately) that appear in other Ack Fics to be in this one. If you have no idea who Ack is in the first place, Then this Fic becomes all the more enjoyable.