Mundo needs a gameplay rework.
You absolutely cannot kill Mundo in lane without help from a jungler. He builds straight tank without the need for damage items (thanks permaslow/% health cleavers/massive AD steroid that made old Sion cower). But all of that could be forgiven... If his ult had SOME kind of cool down. It does not matter how many ignites you have. It does not matter if you have morrellononicon (he never goes below 30% health anyway). Mundo will ult every 20 seconds or so. Something needs to be done about his 0 interaction/ult always up playstyle.