congrats on finishing these! i'm sure they've taken you a lot of time, and it shows you've worked really hard on them.
if you don't mind, i've included a bit of feedback. it isn't intended to be negative, just thoughts from viewer to creator. as a part of my school program we're collectively required to critique a person's artwork for two hours every week. i've always found that these things help a lot, and hopefully this will be helpful to you!
personally, i wish i would see more of your hand (as in using physical materials) in this in either a collage or mixed media work. even if you plan on keeping these works primarily digital, thinking about using your initial workspace and negative space to activate/strengthen your composition (as in, scanning in textured objects such as canvas, paper, etc.) could really add another dimension to these portraits, figurative or literal. if you want to continue working like this, i'd also heavily recommend thinking about what is working within these two images, and what isn't. i think now that you've done two, you can step back and contemplate how to realize these in a more complete way.
i'd also check out the following artists/people. most of this is from the "fine art" world, as i'm not really well-versed in manga or other graphic novels. even if these aren't visually cohesive with what you're attempting to create, i think reading about their ideas concerning text and image might make for interesting research.
edward tufte
barbara kruger
john heartfield (
example)
katsuhiro otomo (
example)
sorry for all the text. just in one of those moods i suppose! let me know if this is helpful or if you have any questions.
ps. do rune next!