Champion Concept: Tirian, The Vessel of Shadows

Hey guys! This is my first concept so please leave your feedback in the comments.

Tirian, The Vessel of Shadows

Passive: Dark Burial (300 sec cd) Tirian Passively has spell vamp. When he dies, he comes back with 50% health and mana with AD,AP,Armor, and MR reduced by 15 for 5 seconds

Q- YOU ARE MINE! (60/65/70/75/80 mana) Tirian throws out a tendril of shadow, pulling the first thing it hits(minion, champion) to him and fearing the target for 1.5 seconds (NO DAMAGE) EDIT: Similar to Blitzcrank hook

W- Shadowstep (40/45/50/55/60 mana +20 per cast) Tirian dissolves into shadow, reappearing on the direct opposite side of the targeted champion, he can use this ability multiple times with mana increase each time (Again NO DAMAGE) EDIT: think of Kassadin ult only point and click on champ

E- Shadow Quake (65/70/75/80/85 mana) Tirian slams the ground, releasing an circle of shadow, dealing magic damage and healing by a base amount for each enemy champion hit. EDIT: Magic damage 75/80/85/90/100 plus (.8 AP) Healing per champ hit 50/100/150/200/250

R- NONE STOP THE SHADOWS (100/150/200 mana) Tirian channels for 5 seconds, pulling in shadows. at the end of the channel, he explodes, dealing magic damage based on how long he channeled for. Reactivating prematurely explodes EDIT: Magic Damage minimum 100/200/300 plus (1.0 AP) Maximum 500/600/700 plus (1.0 AP)

EDIT: Playstyle and role: He is meant to be played as a utility support with moderate sustain, he is built to help feed the ADC kills while not dying himself, I made him to be mechanically difficult to give support players a new twist to stop them from getting bored out of their mind

I'm still working on the lore but please, Leave feedback in the comments