[Gamemode Idea] Unsure if possible - The "Create your own Champion"-Mode

So this mode would work like following:

1.) There would be an extra rider next to the "Profile"/" Hextech-Crafting"/"(Your) Shop" riders

2.) By clicking on this rider a screen will pop up with a Champion silhoutte (maybe no specific champ, rather a more or less human form or smth), on the upper side there would be two ability icons for the Passive + Ulti with maybe a "?" in there and a special edging (maybe flames?) and on the three other sides three normal ability icons for the Basic Abilities with a "?" inside.

3.) As Title/Headline there would be "You choose!"

4.) Then you would be able to chose a Champ by clicking on the Champ silhoutte. I don't know what's the best way to do this, but I guess, the best thing would be to let the player choose Champ and Passive in one - so you can only play the Champ with his/her own passive. By clicking on the silhoutte there would pop up a "Champ Select" where you can choose or search your Champ. After that you could click on the ability icons where the same screen would appear, just that by clicking on the Champ his abilities (or in case of the Ulti) his ability would be to choose.

5.) Example: Champ + Passive: Alistar, his trample-passive Q: Olaf Axe W: Shyvana Fire E: Yasuo Dash Ulti: Poppy Hammer

6.) Then you would have to press a *"Finish"-Button" and you would have this Champ in your champion Pool when playing the gamemode. Maybe you could even have more (up to three?) Champs?

I don't know if this would be possible, maybe some Champs/abilities would have to be disabled/just enabled for some Champs (Jinx' Ulti on Maokai? Maybe somewhat strange shootinga rocket without a rifle/gun/wand... ^^), but imo this would be so fun!