Murkspawn

Hello, I recently made a Nin/Nin stalker, currently level 35, and I have a few questions.

1. Everyone seems to say that Gamblers Cut is better than Sting of the Wasp. why is this? I always tend to take the harder hitting power of the 2 starters.

2. Does smoke flash actually work?

Also, if anyone has a build lying around I can borrow, I would appreciate it greatly. Thanks!