Passive: Rapport - Sven develops a Rapport with enemy champions, allowing him to keep his spells rolling right off his tongue. Each spell that Sven casts lowers all of his cooldowns by 1/2/3/4 seconds.

Q: Misled Intentions - Sven confuses an enemy champion for 1/1.25/1.5/2/2.5 seconds, causing them to walk around aimlessly and dealing 60/80/120/150/190(+0.6 per AP) damage over the duration.
Cooldown: 12/11/10/8.5/7.5 seconds
Mana Cost: 60/60/60/60/60

W: Dirty Crook - Sven protects himself with a spell shield that blocks one negative spell. This shield lasts for 1.5 seconds and if a spell is successfully blocked, Sven temporarily gains 30/40/60/80/100AP. This bonus lasts for 5 seconds.
Cooldown: 20/18/16/14.5/13 seconds
Mana Cost: 80/70/65/65/65

E: Smoke and Mirrors - Sven disappears into a cloud of smoke for 1/2/3/4/5 seconds. Sven's first spell after becoming visible does a bonus 5% (+0.5/1.5/2.0/2.5/3.0% per 100AP) damage.
Cooldown: 18/17/16/14/12 seconds
Mana Cost: 80/80/80/80/80

R: Found the Mark - Sven instantly appears at a targeted enemy's side. This deals 100/150/250 (+1.0 per AP) damage on impact and the target is slowed by 20/40/60% for 3/4/5 seconds.
Cooldown: 20/16/12 seconds
Mana Cost 100/90/80

Sven would be a burst mage, excelling at blowing up targets, most notably after they have done their combos. He could counter other burst mages/champions, by blocking their abilities, disappearing and reappearing with his own Q --> R combo.
His ult has a short cooldown because it is his most reliable damage source, much like Kassadin or Akali. He has a little bit of cc and a lot of counter-tactics. He could be easy to learn; with no skill shots or complex concepts, but hard to master; with a lot of timing involved in chaining his damage.

Thoughts? Comments?