Haha, random characters ftw.
Even though it's the Elsword section and y'know...straying a bit off topic?
Oh well, seems there are enough artists replying for it to not be such a big issue.
The two last characters were my favourite. A lot of creative uses on both of them. Their hair, attire, pose, and emotion all stand out well together!
You should post your traditional works more often! The mouse seems to be limiting your ability on the computer a little. D: I'd just use a dark pen to outline it on paper then colour it on the computer, skipping lineart with the mouse altogether. Maybe it's just me, but I'm not too fond of the use of the "Pen tool" on programs (creates curved lines). >.< Or try saving up for a tablet. They're annoying to get used to at first, but they're well worth it.
But yeah, as for criticism, like Rein already mentioned I think anatomy is the first area to try to improve in. For the two male characters in uniforms, their heads need to be a tad bigger and their limbs need to be shrunk (mainly Cloud). On the first character, his right arm is wandering. xD It should drop by his side, half or more of it hidden by his torso and pelvis. Call me lazy for not completely drawing another arm, but it's just how it naturally is. ^^; Still good practice that you drew another arm though! And remember for his legs, they should both be either fanning out slightly like an upside-down "V" or brought closer together if you want them to be parallel. They are both connected to his pelvis after all.
That's all I have to say for C&C. Keep them coming, and good work!
@Rein: Yeah, it's Kooh. xD