I Think I May Be Stealing Others Artwork!

Okay, I've been hanging out a lot on Deviant Art lately and have been finding out some pretty interesting things about showing your work on the internet. After reading what some rules are to plagiarizing, I may come to the conclusion that my work (such as the Naruto, D-Grayman, and Bleach pieces) may be considered illegal since I did take the poses and such from other art work. So, it's the same artwork only I drew it except for some of it such as the Rukia in the Bleach piece, the Shadowroy piece, and my OC. Even though I did not trace the work, I still feel like it may be wrong. This actually goes the same for any recolors as well. Recolors are considered illegal and punishable by law because I guess you're taking the original pose, scene, character style, etc. and such and just making them a different color. I don't know, it really doesn't concern me since I don't recolor, but I think it may relate to the things I am doing. I don't know. Well anywho, you guys got any ideas if this is illegal or not?

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