He has a lot of neutral-ish match ups that are slightly in the enemy's favor. He is perfectly viable at top, but he has a few things you have to be aware of before you can play him effectively.
You have to be able to use the clone as a shield. If you don't, you will be bullied out of lane by 90% of the time.
If you build damage early, you will hurt a lot but will also be hit quite hard. At lane, his passive isn't too useful (unless you are 5-man ganked, in which situation you probably need more than just that passive). On the other hand, building defense leaves you as armor shred-knockup bot (you can still seriously hurt squishies, though).
Mana costs. Use your clone, but don't overuse it. You have no way to regen mana, and your base regen is quite low.
If you can survive until 6, you can make really good use of your ultimate at setting up ganks/roaming/tp'ing etc. Remember: it's not always a bad choice to ult a single target.
If you like his playstyle, go for it. After a while you will start to get a hang on his w and can go at least even in unfavorable matchups. Also, use his rarity as your advantage. Most people haven't seen him in ages at top and probably are rusty at playing against him.