[Champion Concept] Fenrir The Shadow Hunter

Hey all, first time posting champ concept. My idea is a shadow wolf champ based on the moon/sun theme of Leona and Diana or the theme of the frejord. I'm not sure about the stats and what not. Please feel free to leave feed back or other ideas.

Passive - Every third basic hit applies Hunters Mark - Marks target enemy which pulls minion agro for friendly minions, increased damage and movement speed while moving towards champ which degrades over the course of the mark, and lastly sight around the marked champ that decreases over the course of the mark (when more than one target is marked minion agro is given to nearest enemy champ)

q - Shadow Rend - Fenrir shreds the air and ground sending out a black claw of shadow which deals damage and steals a percent of the target champ's mana and turns it into an aura which increases allied Champ mana regen by the same percent stolen for 3/5/7/9 seconds. The shadow blade can be treated like a projectile and be stopped by Yasuo's Wind Wall.

w - Shadow Dash - Fenrir dashes towards cursor direction if an enemy champ is caught in the dash Fenrir preforms a powerful bite that deals basic damage with a bonus magic damage % based on AP that burns the target over the course of three seconds.

e - Cull - Fenrir growls and barks causing all champions with health lower than Fenrir to be feared then slowed for a short duration. Enemy Champions under 20% health are marked with the Hunter's Mark ability. enemy minions and neutral monsters receive the Hunter's Mark passive and are feared and slowed regardless of health.

r - Pack Hunt - Fenrir howls growing in size and calling shadow wolves to his side, shadow wolves number and and damage is based on AP (possible fun option would be that it turns all friendly minions in an area into wolves of various size that hunt the targeted Champ ignoring everything else) and they can be killed on single hit, however they will proc things like the sides of Thresh's box or Teemo's mushrooms if they run into them. The wolves have 5% increased movement speed based on Fenrir's movement speed on cast and only target Fenrir's target for the r proc. Fenrir's Pack hunt grants him increased size, movement and attack speed and reduces the effects of stuns and slows. Attacks on Enemy Champions under 15% will inflict grievous wounds.