If we don't get URF again let's get this:
Allow us to stack Unique prefixes from all items to make God builds.
Want to build 3 
? Or how about six 
? Of course 
will have to be removed entirely from this game mode.
That is all.
How about USF mode? Ultra Slow Fire. Attack speed is halved and CD is reduced by 80%. Really gotta make your moves count!
How about Shroom wars? 5 vs 5 on SR, and all 10 players are Teemo.
I want "Friendly Fire Mode"
Maybe Homeguard mode? Everyone has Boots of Mobility with unending Homeguard effect. Zoom around the map and join in endless skirmishes. Of course, Hecarim won't be available.
What if Riot made a really blind game mode where the screen is permanently zoomed in 100%, the minimap is removed, and a demonic poro king invaded SR and we had 
.
Demonic poros will attack both sides, but similar to showdown, doing something will allow one side to create temporary allegiance with the king. Then riot can nerf lee sin (that's the april fools joke).
The end.
how about, creating custom move sets. for example you ban 3 on each side then everyone picks a champion. after you pick your champion, a menu opens and you select your passive, q ,w, e and ult. for example imagine a lucian, running around with J4 passive, lee sin q, kog maw w, gnar e, and darius ult (WOW LUCIAN ULT DOES DAMAGE!) yes? no?
