[Champion Concept] Hemlock (The Plague Doctor)

Taking a stab at my first champion concept so constructive criticism is appreciated! Numbers are not set in stone; they are meant as a reference to give you a general idea of potential power. (I used numbers from other champions and slightly modified where applicable). I'm not a math expert so some abilities might be under or over-powered.

The champion doesn't have a backstory yet, but the game play idea was based around a champion that could impose status ailments both good and bad on champions, i.e. increasing damage over time effects, limiting movement abilities, healing allies and preventing minion aggro with passive.

Hemlock (Plague doctor) Support Mage?

Passive

Sanitation Range 450 (Self) Damaging Grounded enemies heals Hemlock and nearby allies for 5% percent of damage done Additionally auto-attacks proc sanitation. At 3 stacks become immune for 3 seconds to minion aggro.

Q: Bubonic Plague Cooldown: 17/16/15/14/13 Cost: 50/55/60/65/70 Mana Range: 1175 Skill shot, fling an infected bird at enemy target grounding enemy for 1/1.5/2/2.5/3 seconds Increase damage over time effects from all sources on grounded enemies by .5/1/1.5/1.8/2 seconds

W: Avian Flu (or "Birds of Prey"?) Cooldown: 6/5.5/5/4.5 Cost: 50/55/60/65/70 Mana Range: 850 Fling infected avian egg that explodes on impact poisoning enemies for 40/65/85/110/130 (+60% Ability Power) Magic Damage per second for 1.5 seconds, Range 850

E: Bubonic Ooze Cooldown: 17 Cost: 40 Mana Range: 450 (self) Deals 20/45/70/95/115 (+70% Ability Power) Magic Damage per second for 2 seconds to enemies it passes through and leaves a trail on the ground for 4 seconds, briefly slowing enemies in it by 20/26/36/42/48%.

R: Black Death Cooldown: 120/105/90 Cost: 100 Mana Range: 5100 Launch a swarm of infected birds that explodes on impact Reducing the mana and energy of enemy champions by 50/55/65 percent, additionally reducing regeneration of both mana and energy by 50% for 3 seconds.

General Champ Stats (Pulled from Morgana) Health:
547.48 (+86 Growth)
Health Regeneration: 5.708 (+0.6 Growth) Mana: 340.8 (+60 Growth) Mana Regeneration: 8.5 (+0.8 Growth)

Attack Speed: 0.625 (+1.53% Growth) Armor: 25.384 (+3.8 Growth) Magic Resists: 30 (+0 Growth) Attack Range: 450 Movement Speed: 335

Cons for this champ would be no hard crowd control (stun, taunt, fear or binding), ult does no damage, and passive is not as useful out of laning phase. I was thinking about adding a fear effect to the ult but didn't want to overload the champ. If it were to go support there are not a lot of champs that deal damage over time. It would, however, have potentially good results if paired with a Ziggs bot.

If this is popular enough I can get artwork done on the character and abilities. Thanks in advance for the input.