This work seems overated in my opinion. The naruto guy in the first one is just awful in my opinion, ruins the simplicity and originality of the signature. Replace him, and put a glowing yellow, that is almost like sunlight in his place and the contrast and simplicity in the piece will be amazing. Second one seems horrible to me, nothing really blends with the render, and the pen tool just looks like a distraction point to keep your eye away from the boring top half of the piece. The lines need to be getting darker as they stretch outwards to blend with the piece, they also need slight sharpening too look more realistic.
All i have time to write at the moment.