I think I just found out why Rumble is so freaking annoying to play against
His Q has a huge base that barely pushes the wave(deals less to minions and monsters), it has a 1:1 AP scaling ratio, it has a really low cooldown, danger zone makes it deal 50% more damage which becomes insane, and his shield scales off AP(not a huge issue imo, but it has a low cooldown).
Also his super galaxy skin is piss ass annoying to play against.
SUPER GALAXY COMBO BREAKER spammed 10 times every minute, fuck.