A pretty cool concept for a new champion

The champions name is Raystorm, the lighting angel. he wields dual swords made of energy, has black, angel wings, and wears dark green armor with sharp claw-like fingers, thin, curved spikes protruding from the shoulderblades and no helmet.

(This concept is still exactly that, a concept. so please bare the op-ness and give suggestions for balancing.)

basically, the champion would be a pseudo-ranged ap carry. instead of trying to explain what i mean, i'll just say what his abilities are, then it should make more sense.

passive: upon killing an enemy, receives 50/70/90 mana immediately(upgrades at levels 5, 10, and 15)

Q: Toggle: While active, Raystorm combines his duel swords into a bow that fires lightning arrows, consuming 40 mana per shot and dealing 6%/7%/8%/9%/10% of ap in bonus magic damage.

W: Raystorm stores up to 3 charges and can consume a charge at the cost of 100 mana to teleport to the location of the cursor(exactly the same as flash, and same range). upon learning the ability, they get 1 charge immediately, a new charge is stored every 80/75/70/65/60 seconds.

E: Raystorm shoots a bolt of lightning at the target, silencing for 1/1.25/1.5/1.75/2 seconds and dealing 30/50/70/90/110(+30% ap) magic damage. cooldown: 15/14/13/12/11 seconds.

Ultimate: Raystorm channels for .5 seconds then dashes to and through the target champion instantaneously(untargetable during) dealing 150/300/450(+40% ap) magic damage. The distance traveled to the target is the distance traveled past the target following in the same direction. Cooldown: 90/80/70 seconds. Mana cost: 150/175/200.

explanation for abilities and passive:(cooldowns manacosts and damage are all subject to change) basically, you have to be flawless at last hitting with this champion in order to profit from his passive, due to the fact that his Q consumes 40 mana per shot and the passive only refunds 50 mana to start if you kill a unit. i feel that the high manacost of his abilities and the high cooldowns allow him to not be too overpowered considering he can flash 3 times at will as an ability(also note, he will be starting with considerably low maximum mana to combat the strength of his abilities). His W is pretty straightforward although the damage and silence times need to be tweaked a little. To explain the ultimate; basically, if you use the ultimate at max range and the target champion doesnt move at all, you will end up the exact distance on the otherside of the target as you started. The ability is targeted so traveling out of the range of the ultimate after it has been cast but not completed will not stop it from completing, but becoming untargetable will. the dash is instant but leaves behind a blue lightning streak after it finishes to symbolize him moving at the speed of lightning. for the ranges of his abilities, his Q-enhanced auto-attack range is slightly farther than vaynes(as a comparison only) the range of his E is slightly farther than his Q-enhanced auto-attack range, and the range of his ult is ~80% of the distance a champion can see(as in, what a champion in general could normally see, not what any champion on the map sees)(not sure on exact values cause i dont know how distances are measured in league).

That pretty much sums up Raystorm, the lightning angel. If you guys have any questions, feel free to ask, and any help with balancing the damage and ratios and all the fine-tuning would be greatly appreciated.