Gangplank

Gangplank has a worldwide ult, does too much damage to turrets after 5 minute mark, has a CLENSE that basically nullifies taunts and other things (his citrus fruit), and has too much movement speed. Barrels are just full of overloaded power too.

Nobody should be this strong in the game. Why give gangplank a worldwide ult when he can just walk to anywhere on the map in a matter of seconds due to his passive after exploading a barrel? Couldn't riot at least nerf his barrels to reduce placement range or damage? I know they don't stack on each other but the cd's on his barrels are too low even without cooldown reduction.