Rotating game mode: Hide and Seek!
Of course, this is NOT a new idea but I just wanted to share my iteration.
It would take place on the same map as ascension and you can choose which role you would like to play before entering the queue. It would be 2 hunters vs 5 hiders and hiders would be limited to only movement items. Hunters do not take any damage but they can get cc'ed as usual. Once the clock hits 20 minutes the match ends. Hunters win if together, they rack up 10-15 kills; otherwise, hiders win.
Most stealth champions would be banned except champions that can't abuse stealth as much as others can:

another big plus to this is that it would take very little time for riot to implement this as it does not require any extra art assets or anything of that matter; just a little coding.