Kogasa!
![](http://i.imgur.com/1WW7imJ.jpg)
But if we're being serious, I think Yukari. Borders cover pretty much everything.
Remilia is a strong contender depending on just how directly she can control fate, I don't know if there's ever been an official statement about it.
If we're talking who would win in a serious fight rather than general strength though, Sakuya'a time manipulation is pretty terrifying.