Figured this would be an appropriate enough place to put this.
I was messing around with Skywrath Mage last night, and he is a very strange character.
His Q is a very standard damage dealing shot, whereas his W is a homing shot that targets the nearest enemy hero, slowing and dealing damage. E is a silence that causes spell damage on the target to increase, and his ultimate is about the smallest template weapon I've seen, though does horrendous damage.
When carps and I played against him, he was REALLY causing us problems, with the amount of early damage he was putting out, but I really really struggled for mana with him, as well as finding him about the softest character I've played. I was dying ALL THE TIME, and this is the new, more careful me. I would suggest that he's not fun to lane against if he's laning with another ranged character, as the amount of damage he can put out in that situation is horrific, but there's no chance he'll survive if he goes near a tower at all. Suspect he could turn out to be very difficult to use. Worth targeting early in a teamfight purely because he can't take any punishment, just to sort out the numbers. Not a fun opponent for melee characters, as his spells have quite good range.