We need a "Champion Test" custom mode.

So I made a custom game earlier today and was practicing animation cancelling with Riven. I started to practice with flash, and I realized that I had to wait the FULL flash cooldown if I wanted to practice using it seamlessly in the combo. I'd really, really like to see a custom mode that just had a derp model of a champion and a derp model of a minion that you could practice using abilities on with the ability to turn off cooldowns on summoners and abilities. Bonus points if you could configure movement and build of the champion and have a mock minion line for those Luxes out there to practice waveclear.