M is right about the chest area, but I'd also get rid of the seem in his lower arm and even out the skin between the thumb and index finger. It looks a bit folded.
Very good mask btw!
Also there's this site that has a lot of free 3d models, including a ninja. If you don't know it, I'll upload the scene for you.
<a href="https://www.d2lodshop.com" rel="noopener noreferrer nofollow" class="giveMeEllipsisa" target="blank">D2lodshop</a>
<a href="https://www.gatcity.com/forum/forumdisplay.php?f=3" rel="noopener noreferrer nofollow" class="giveMeEllipsisa" target="blank">GAT City</a>
<a href="https://www.rhymbox.com" rel="noopener noreferrer nofollow" class="giveMeEllipsisa" target="blank">XMPP instant messaging</a>