Dude, love how you've managed to make it look as if the mask can just go off and on. (Should make an animated gif of that or something, hmmm... focusing!) Either way love the mask designs and how 3D they are in the artwork, but I do have the issue they might that the bottom one is a tad too small. That's my opinion anyways.
Also like how you got the emo guy's eyes, they look... so emo. Telling me 'I just don't care'. The ink also goes on so well, I love how you've gotten the black and white, oh it's gorgeous.
But I do have issues besides the bottom person's mask being too small. Apologies if I'm being rude for giving criticism. Probably risky considering I'm not as good at drawing/painting as you Ari-6. But I'm certain I have a right to my opinion. So yes, while the top guy is also lovely, I think you could've done the ear better, I just find it a bit too pointy and somehow looks removable. So yes, I'm saying I don't like the ear, but I will confess that I hate ears in drawings like manga and feel they ruin my artwork when I put ears on (So I tend to put lotz of hair around them). But saying that, the bottom guy's ear is an AA+ considering you have someone who just confessed to hating drawn ears.
Another issue is the top guy's hair. I'm not sure if you did it intentionally, but his pieces of hair looks like if you pulled on it, it would snap. But then I'm comparing this to the bottom guy again, whose hair looks like if I ruffled it, it would feel 'almost' like hair (Well it is hard to draw realistic hair in manga).
Anyways, love it, splendid artwork and just trying to improve giving art critique for this other forum I'm in where you're kind of expected to give decent art critique. Anyways, hope it also leads to helping you Ari-6.