[@Tachi] For the most part yes. Specifically it increases his attack strength, and makes it slightly harder to see where the blade itself is, making it harder to block. Not only that, but anything that is weak to dark based attacks takes additional damage. However, bright light (like the noon sun for instance) weakens both the damage increase and the difficulty to block. Training will fix this (as he learns to absorb the light through the shadows) but that is months, if not years, away depending on how he is trained.