Possible New Idea for A Mid Lane Mage.

I've came up with an idea for a new type of mid lane mage. One that can pack a punch in team fights. Here are my ideas for one! (Name is undecided) The Harbinger

Passive (Ascending Power) : Whenever (UNDECIDED) casts a spell and hits successfully on an enemy champion the next ability (UNDECIDED) casts will become augmented. (Augment ideas could be, next ability can root or slow etc.)

Q (Harvest) : (UNDECIDED) begins to sap an enemy champion's HP and Mana. (UNDECIDED) is rooted during the duration, but then can cancel the sap anytime.

W (Asorb Power): (UNDECIDED) shields him/herself and blocks the next enemy ability. If blocked (UNDECIDED) next auto attack will be augmented and a small shield will be formed. (Augmentation could be deal bonus magic damage etc.)

E (Death's Charge WIP Name): (UNDECIDED) casts Void Soldiers that knock back and deal damage in a direction that (UNDECIDED) pleases. The Soldiers disappear after their charge.

R (Black Hole or Death's Grasp): (UNDECIDED) casts a huge circle that draws enemies in the center slowly. You are slowed by 25%, while in the circle. Enemies take damage, that ascends the more they stay in it.

Please place any suggestions, recommendations etc. I'm always open for change.

-Bardbattle