Just an Idea for a new champ

Updated Champion I know mana drain champs have been tried in the past, and failed. However, I think this dude would balance that:

Lore: you know, in the Hobbit movie, that old naturey wizard? I forgo this name, but this guy would have a lore like him. maybe related to maokai in some way.

Passive (more complicated than jhin's):
1 - His autoattacks use mana (think jinx rockets), and deal a percentage of AP (30%?) 2 - his mana pool has infinite capacity, but no regen 3 - He passively absorbs 25% of mana used for spells in his vicinity, both his allies and enemy's, and deposits it in his mana pool (half as effective for energy and other non-mana spells)

Q - Sets a visible, untargetable 'trap' that drains mana from champions/minions that cross over it. If the champions/minions have <50% of their mana, drains health at half effectiveness. lasts for maybe two minutes, and can have a max of five at a time

W - A slowing skillshot.

E - Sets up a turret that will do his autoattacks for him (like Azir), at half the mana cost. last 30 sec.

R - A massive AOE, that drains 25% of everyone's mana, and deals all that in damage, equally over every entity in it's region, including minons. So it is basically trahs inlane, but when there are teamfights near, say, dragon, it becomes rather helpful

*All of his spells are free, Garen style. long cooldown, though, on Q/E.

I was thinking this guy could serve as an anti-healer supp, or a mid-laner. He could also mildly counter mid-laners that use resources for spells (so, everyone but Katarina), and encourage weird matchups (like a Garen mid. Haven't seen that in a while, have you?)