Champion suggestion: Necromancer

Hi! here's a champion idea i had today. Shadow Islesy name, the Necromancer's Disciple or some necromancy epithet

Necromancer is a squishy caster who grows significantly stronger as the amount of dead people around him increase.

Passive: Champions and Large Minions and monsters that die when Necromancer is on the map spawn a tombstone where he or she died. Tombstone lasts for as long as the champion is dead. (or for X seconds for large minions or monsters) When Necromancer is within X units of gravestone, he gains Y AP/AD/MR/Armor/MPen/ArPen. Necromancer gains a small speed boost when he is walking towards a tombstone

Q: Redemptive Grasp Necromancer marks a unit. if the unit dies, Necromancer heals himself and nearby allies for stacks of Carnal Demise (*AP scaling). marking an enemy will deal X damage over the duration

W: Shed Flesh Necromancer sheds his corporeal aspect and manifests as a spirit, becoming untargetable for 1/1.5/2/2.5/3 seconds and allowing him to pass through units, dealing (small) damage to enemies he passes through, and gives him the ability to cast "Spectral Surge"

E: Spectral Surge Passive: Gain stacks of Carnal Demise for each unit that dies around Necromancer Active: Neromancer surges forward, damaging all units struck. If Necromancer strikes an enemy champion, he latches onto him, slowing him until he returns to his corporeal aspect, dealing damage per second equal to stacks of Carnal Demise(* AP scaling)

R: Hope for the Damned After channeling for 2 seconds, Necromancer calls up the spirits of the dead in a large area. every tombstone in a large area around Necromancer releases the ghost of the Champion trapped there, which attacks the nearest enemy of Necromancer

His ultimate would have a large impact in teamfights, and there's a wide flexibiliity for when he casts it to provide different results: early in the teamfight and it gives his team an extra edge against the other team, or makes up for his teammate's death by having his ghost fight for them. or he can wait in the back line with some heals on his Q, waiting for people to die, giving him bonus to his abilities and survivability, especially his ultimate.

Honestly, i think the passive and Ultimate are the important parts of the champ. his QWE can be anything else. I'd love to hear your ideas!