It feels like Mundo simply cannot be beaten by a Rumble, especially if Mundo gets ahead. Spirit Visage gets rushed, and then Rumble can't kill Mundo no matter what he tries. And delaying stuff to rush Void Staff is just shooting yourself in the head.
Bad matchup?
EDIT: Hell, Mundo himself is just obnoxious to fight. Builds 5k HP and still hurts like crazy while having skills that you can't easily outplay. Toxic kit is toxic.
Flaherty1 votesYou can poke him through minions, he cannot. Take advantage of that and his early game when he's not an unstoppable monster building full tank. Grievous wounds stops most of his ult but unfortunately morello isn't good on rumble so maybe take ignite if you're facing him.
Automated Riven1 votesmundo is a lane that you have to kill before six. or else there isnt really much you can do. take ignite and ask for a gank. or else your gonna have to use tp to get some really good ganks off. also rush rylies liandries and void. doesnt gimp your teamfight and allows you to actually do damage to mundo should a fight happen. (ask your adc to get executioners calling and even the jungle for teamfights)
PermabannedGaren1 votesIf you don't get a good lead early on then no, not really. Not many champions can really fight Mundo by themselves once he gets some of his items coming into the mid game. He's virtually indestructible but deals solid damage.
Lord Desert1 votes
, heard of this?
darkdill1 votesMundo laughs at that when he has 
and 
.
Lord Desert1 voteswatch him burn to a crisp with and 
in seconds. push him under turret too and then poke and slowly drain his will to life
darkdill1 votesMaybe I need to iterate: MUNDO SNOWBALLED.
Lord Desert1 votesok, then it might get a bit more anyoing. If reallyreally far behind:
to stall/bind him at lane, or just play alot more passivly and rekt/zone the backlane in teamfights, while mundo takes all the dmg in the frontline so you can seperate him from his team, that should be good enough too
Lord Desert1 votesso see, still pretty easy to keep mundo down, if you know how too ;P
DunkinNoobs1 votesMundo does well against AP champs in general. Nothing Mundo loves more than to go top against some AP champ and be able to rush spirit visage.