Looks fine, but like the concedes said, you need to tune up your build. You have to many quint runes to start with. But from what I can tell the text from the guide is fine. You can also put your items into icons by using .itemname. Just rework it a bit, but for now I'll give you a +1.

Not my favorite Twitch build, I'll explain why:

1. Dagger is, if you ask me, a very weak starting item, even for Twitch. 10% AS increase is pretty negligible. If you need AS, you could get it in runes. I'd rather opt for something that gives him either durability or dmg.
2. You don't get a point in W early. The slow on this is so awesome and useful, in both ganks and teamfights, why neglect it?
3. No ghost/flash. I think if you put a point in W, you wouldn't need either exhaust or ignite. Again, seriously limiting your survivability for only moderate offensive increase.
4. Not enough empathsis on leveling expunge. You don't need all those levels in stealth early imo. I'd rather level expunge and be able to finish better, especially if I'm not putting a point in W.

Btw, just so you know, you put 6 points in expunge and only 2 in the ult.

Please comment :)!