Somnolent, The Gradual Sleep

Somnolent is a creation of Zaun, transformed by the powers of Singed's chemicals, and released upon an unready world. Zaun has used him in battle as a sleeper agent to turn the tides of any war. But this is not just some title for Somnolent. He literally makes enemies fall asleep. Singed's chemicals have altered his body to release a neurotoxin that causes people to drift into sleep. Because of his abilities, Zaun has used him to crush their enemies. (lore could use fleshing out obviously)

Somnolent is a support that uses his abilities to make his enemies fall asleep. He uses the neurotoxins that seep from his body to cause sudden onset of sleep onto those that come in contact with Somnolent.

Passive: Gradual Sleep Somnolent oozes a sleeping toxin that begins stacking drowsiness onto enemy champions. After a certain amount of stacks, champions begin to have an increased chance to fall asleep on the battlefield for a short amount of time. Stacks are gained faster depending on how close Somnolent is to the enemy. Enemies will not fall asleep while Somnolent is dead.

Q: Yawn Somnolent fires concentrated sleeping toxin into a small area, causing enemies who spend two seconds in it to fall asleep for a short time.

W: Healthy Sleep Somnolent causes an ally champion to go to sleep. While asleep and out of combat, the ally has increased health and mana regen, as well as cooldown reduction. The ally champion can choose to wake up whenever they desire, ending the above effects.

E: Delayed Action Somnolent releases toxins into a designated area, causing all units passing through to delay their movement for five seconds. Units can only be effected by this ability once every three minutes. Somnolent can reactivate E to absorb the toxins back into his body, removing them from the field.

R: Slumber Somnolent causes himself to fall asleep, causing toxins to overflow out of his body. If these streams of toxins hit enemies, their Gradual Sleep stacks will have triple the chance of taking effect. Somnolent cannot move or attack while using Slumber, but can reactivate Slumber to exit sleep. If killed in Slumber, death timer is reduced.

So this is my concept of a sleep-causing champion. His passive will gradually cause champions on the other team to fall asleep, which can be deadly if the stacks decide to proc during a team fight. Yawn is kind of like Soraka's E, Equinox, where you have a small area, but instead of rooting if you're in it when it ends, you'll fall asleep if you're on it for long enough. Healthy Sleep is a "rest" ability, allowing a friendly champ to regain all of their resources fairly quickly without having to recall. Delayed Action is a great ability to help get your lane pushing. It delays minions, so that you can have a large minion wave at one point, which should push your lane. A lot of possible strategy here. Slumber is a dangerous ability for both the enemies and for Somnolent. Somnolent is extremely squishy, so even if he is able to use Slumber before a team fight, enemies will know where he's at, due to his streams of toxins, and he'll be an open target, easy to kill. And if he dies, then sleep can't hit enemies at all.

Also, Somnolent's allies receive a passive bonus called "Gas Mask" that makes them unaffected by Somnolent's effects.

Let me hear your thoughts, problems I may have missed, etc.