Pile Guy, the Guy that uses Piles

This is just a rough champion concept that spawned from a want to have another tankish supporty champion. The numbers are mostly just placeholders, but they are in the ballpark of where I think they should be. He doesn't have a name so I just took to calling him Pile Guy.

(Passive) Ooze Every 6/5/4/3 seconds while moving, Pile Guy leaves behind a Pile. Whenever an enemy steps on the Pile, it is consumed and the champion is slowed by 50% for .5 seconds. Whenever an allied champion steps on a Pile, they gain a burst of speed. Whenever Pile Guy steps on a Pile, his next basic attack deals 10+(5 x level)(+10% AP) bonus magic damage. Piles last 5 seconds.

(Q) Belch Pile Guy spews out slime in front of him dealing 60/95/130/165/210(+60% AP) magic damage in a cone and creating 1/1/2/2/3 Piles in random locations within the AOE. CD: 10 seconds Mana Cost: 80/85/90/95/100

(W) Hurl Pile Guy lobs a ball of slime at a target location that explodes on impact, nudging all enemies away from the blast. This ability deals 50/70/90/110/130(+40% AP) magic damage and detonates all piles within the AOE. CD: 13/12/11/10/9 seconds Mana Cost: 80

(E) Overflow Pile Guy leaves behind a trail of slime and halving the cooldown of Ooze for 5 seconds. The trail deals 4/5/6/7/8(+1% AP)% of the enemy’s maximum health as magic damage every second. CD: 20/18/16/14/12 seconds Mana Cost: 100/110/120/130/140

(R) Instability Passive - Shortly after a Pile is stepped on, it explodes dealing 20/30/40(+10% AP)(+2% bonus health) true damage. Active - Pile Guy explodes himself into 20 Piles, reducing himself to 1 health, cleansing all debuffs, and becoming invulnerable. After 4 seconds, Pile Guy reforms and absorbs all Piles around him, healing himself for 5% of his amount of health at the activation of this ability for each Pile absorbed. CD: 120/110/100 seconds Mana Cost: 150

If anyone has comments I'll be happy to read them.