I can't be the only one who would like this? Personally the Jinx log in was my favorite and would love to be able to switch the log in screens often. Hell, I would even spend IP or RP in order to do so!
I really loved the Gnar log in, how his eyes followed the firefly and it should the screen with him.
Lucian/DJ Sona/Urf logins for days
Look up a program called "LSI" (League Summoner Info). It lets you do this and so many other things that are regularly requested on these boards.
Panth smiting red buff, tho? THE MUSIC, AHH THE HORNS
