Mundo Passive Change.
Currently Mundo's passive is a 
1.5. That's exactly it, in fact. So I suggest that it get replace with this: Mundo's health regen increases by 1/1.5/2% for every 1% of missing health.
Like Veigar's passive, but with health regen. Any champion can become Mundo with a . Mundo is at the bottom of the meta, with a 2.27% popularity and 45.45% winrate. He's pretty obsolete.
He's due for a change or two, the last change was 4.2 and it was a cleaver width nerf.
