Ghost / Spirit Champion Concept

I've been wondering how a real ghost / spirit would feel on the rift. By that I mean a ghost that interacts by possessing things on the rift.

I imagine this ghost to be a female and very serpent-like (But that doesn't really matter) Lets just call her for Ghastly now. Ghastly would work best as an support, which is kinda problematic at the moment, since Pyke just came out... Any way-

Her Passive could be called Spirit Walker: While Spirit Walker is active Ghastly is untargetable, BUT! she can't attack either.

Q would definitely be called Possess: Ghastly enters the body of whatever she chooses, that includes: Champions, Minions, Towers and Jungle monsters. Ghastly takes full control over friendly towers, and any minion. On minions Ghastly creates a small zone where all minions within gets affected by her other abilities. While possessing, Spirit Walker deactivates, and all incoming damage is split between Ghastly and the host. Even if the host is an enemy. By pressing Q again, or if the host dies, Ghastly de-possesses the host, and Spirit Walker becomes active again.

W & E is only usable while Ghastly is possessing some thing, and changes depending on the host.

W: Gives a +20% boost in attack speed and movement speed on friendlies for 5 seconds (Towers gets +50% attack speed, since they doesn't move). And the opposite on enemies obviously.

E: On friendlies, Ghastly adds her own defense Stats onto the host for a few seconds, and on enemies she removes their defenses with her owns. Minions only get half the values, but multiple are affected.

R: Can be on dead allied champions while not possessing anything, Ghastly becomes targetable and channels for 3-5 seconds, before sacrificing herself to revive the allied, and be given Ghastly's current health. If the allied receives more health than he haves, the additional health becomes a decaying shield. On a possessed mionion, nearby friendly minions will move to the position of the cursor, or attack target. Minions will return to their original lane, if they gets to far away from it.