Trickster champion concept

So I have the beginning of an idea, I was wondering if anyone had suggestions of how I could take this further or changes I should make. The idea is basically a burst mage or assassin who relies on trickery with portals and unusual angles of attack

Q: Summon a projectile at a chosen range, the projectile will then fly towards the initial cast location a set distance. If this ability hits, you may fire a second projectile originating from the character model

W: Create a pair of portals in a line. The farther away they are placed, the farther away they are spaced. Skillshots are able to travel through from one portal to the other, and will leave at the same angle in relation to the portal that it entered with. Both sides of both portals behave the same way. Target 1 of the summoned portals and reactivate this ability to "flip" the polarity of that portal, making skillshots come out of the opposite side of normal

E: Teleport a short distance, then fire a projectile towards where this ability was cast from

Some ideas I had were either giving you a stun if you were able to hit a champion from opposite sides with skillshots in a short amount of time and giving enhanced effects to your own spells when you shoot them through your portals for more options, but I have no idea what to do for an ult