But you did get me curious. Have you heard of parallels? I just confirmed it will run on iPad...
http://www.parallels.com/
This is the go-to program for running windows on a mac (at least it is for my circle of mac users). I have a lab-mate who uses this to use crystallography programs, graphics programs, etc. for things that won't run on his mac.
You will need to buy this and a license for Windows 10. The big issue is whether or not your iPad is powerful enough to run LoL while running parallels without crashing or dropping the FPS to unplayable highs. I would try to google around and make sure LoL will actually run on an iPad before spending money on that stuff, personally. You're the first person I've ever heard of to try.