Grolmog - The Demon Caller

Grolmog was a concept I created while thinking of ideas for a mid-laner mage character. Most of his character and ability concepts were built around his passive which developed into the idea of a demon-summoning sorcerer. From that point, his abilities seemed to develop naturally during my concept creation. My biggest problem with Grolmog was trying to make his abilities fit together into a comfortable kit, and I am aware that I have not entirely achieved that goal. So, if you have any ideas of how to alter my design in order to bring some cohesiveness to him, or just feedback in general, it would be greatly appreciated! Thank you!

(passive) Haunting Sins - Whenever an enemy champion kills any ally, they are haunted by the soul of that fallen ally and receive 1 stack of "Haunting Sins". While carrying stacks of "Haunting Sins", Grolmog's abilities deal 1% (per stack) of the targets maximum health as bonus magical damage. An enemy can only carry a maximum of 10 stacks at a time (equaling up to a max of 10% bonus damage) and all stacks are lost upon death. "Haunting Sins" bonus damage can only activate once every 8 seconds.

(Q) Death Grip - Grolmog summons a pentagram at a target location. After a .5 second delay, ghostly hands lash out and any enemies on the pentagram take magic damage and are tethered to the center of the circle. **Tethered **enemies can not travel further than 800 units away from the anchor point until the duration ends. Damage : 60/85/110/135/160 + 65% AP Tether Duration : 2s Cooldown : 10s

(W) Nightshade - Grolmog casts forth a misty cloud of shadows toward a target location. Upon reaching it's location, it obscures the vision of all enemies inside the cloud and hides all allies from vision outside of the cloud. Duration : 3s Cooldown : 13/12/11/10/9

(E) Vengeful Spirits - Summons a swarm of angry souls from the underworld that travel inward toward Grolmog. Any enemies hit by the spirits take magic damage and are knocked toward Grolmog. Damage : 60/90/120/150/180 + 70% AP Cooldown : 13/12.5/12/11.5/11

(Ultimate) To Hell and Back - Grolmog opens a portal directly to the depths of the underworld. After a 1.5 second delay, the portal snaps shut and traps all enemies caught by the portal in a stasis for 1 second. Trapped enemies can not move, attack, or use items while in the stasis and take magic damage upon being released from the portal. Damage : 200/350/500 + 65% AP Cooldown : 90/75/60

Thank you once again for reading and leave a comment if you enjoyed, have feedback, or for any other reason. It is greatly appreciated!