Then use your Q on him and make him run away.

Maybe it's just me, but if weekly free champions is a problem in ranked games, banning them from ranked games wouldn't be too crazy. After all, presumably in a ranked game you should actually know your champion and be pretty good. Since you get ranked and all based on how the game goes.
Whereas in normal games, you win some, you lose some, and it really doesn't matter much either way within a minute of the game being over. That is why people play multiplayer games after all - because winning all the time easily like most single player games offer tends to get...repetitive.

+1. In this case, or life in general, it's about the journey; not the destination. When you make music. When you draw. When you write literature. When you play League of Legends. If you're only in it to reach the destination right away, you will be missing out on the experiences and memories along the way that carry you forward. Correcting errors during editing, rough drafts, and compositions is part of the learning process. Being "Unstoppable" right out the door is depressing. I'd hate to all of a sudden know how to be a novice swordsman and then I wake up conquering a continent. No way...I want to go through the full journey; the full experience. Starting from the very bottom. So I can work my way up and never be Done till my last breath; and maybe not even be done then.

Oh no! I cant play ranked now! Riot just force me to buy new champions as far as I have Soraka and Kassadin in my posession and not 14 champions total...

Plus they call Kassadin "Melee DPS" when I cant see the big difference in new Kass making me wanna play him as mage...