Yorick Rework
Since he's just clogging up your servers with his useless data, why don't just delete him?
Or, here's a better idea! Rework him rather than your 120+ champ list who don't need reworks!
NEW CONCEPT: Yorick doesn't use pets or ghouls. Riot, let's be frank, you guys SUCK when it comes to pet controls and balancing things of this nature. Characters like Venomancer and Visage in Dota have pets, and they have special traits like immunity to magic and lowered target priority as a factor to make them not worthless gold presents to enemies. You guys would need to make Yorick's ghouls immune to all forms of AOE damage and stop the HP from being the timer counter for the ghouls to work.
I don't think your team has the capability to do something like that, so let's just scrap the whole thing.
NEW TITLE: Yorick, the Gravedigger
Passive: Denial - Enemies near Yorick suffer from lowered resistances and movement speeds based on their missing health. These penalties cap at % of max HP. These penalties increase as they move away from Yorick. Anger - Enemies in a target area are debuffed with a taunt toward Yorick, causing them to run towards him and only attack when within melee range. Bargaining - Enemy units suffer a damage over time in a fixed area of effect that scales on max HP, healing Yorick for the some of the damage dealt. Depression - Saps movement speed from enemy champions in a target area, giving bonuses to Yorick and half that to his allies. Acceptance - Curses an enemy champion, granting true sight and amplifying damage that they take from all sources. If the target dies while under the effect, the cooldown is refreshed.
This, as a result, will change his role significantly from... Well, NOTHING, to a support/teamfighting role. He can soak punishment and set up for pick offs, while being a good front line support rather than your standard peel or heal support.