Dr. Mundo is one of my favourite heroes. When i do well with him i rip people in half in seconds.
However i believe this game is extremely biased against a champion such as Mundo.
He damages himself constantly, his unique prowess is his ability to keep going and going without mana hassle, not unique in and of itself but with his ultimates regen it makes him unique.
Now with items like exe calling and spells like ignite i believe his uniqueness is turned in to pointlessness.
Using his ult with the heal debuff on you actually helps them kill you faster because it nukes you for 20% of your health. Then regens for 25% with debuff, how is that fair that ONE auto attack can make his ulti completely worthless except for a movement speed inscrease or some quick regen in the jungle to reccuperate?
I personally believe there is no place in this game for Executioner's Calling and the reason for that is because the damage:survivability ratio in this game is flawed, the damage is insane.
I don't think there would be ANY negative effect if exe calling was flat out removed from the game. You should not be able to nulify items and ultimates, spells and HEROES for 1350 gold that is obscene. Mundo would not be overpowered if his ulti was allowed to heal for it's full amount, you can still dps him down ALONE through his ulti regen -_-.
I know how to build mundo, i play him as a ganker/hunter/chaser because thats what he is FORCED to be, with his ulti he should be able to be so much more but currently he can't because of the -50% healing/regen debuffs in the game.