New Game Mode Event Idea

In light of the Bilgewater Event, I had an idea for a new game mode event that could appear in the future.

My idea:

on champion select you pick a champion but that only gives you the character look and not their abilities. The special aspect of the game mode will be that you are randomley given a passive Q W E R from any champion. For example having Volibears passive with Cho Gath Q, Le blanc W, Riven E, Ezreal R.

Your randomly given moves will show before the games begins, with time allocated to allow you to re roll 1 ability. Re-rolls would work like how ARAM Champion re-rolls work: Max of 2 and they have to be earnt by playing the game mode. However there would be no trading abilities between players.

Please post your thoughts on this idea.