I regret to inform you that this is considered art theft and is not tolerated on DA. Coloring over, editing, or submitting a picture that is not yours without proven, written permission from the original artist is a violation of DA ToS and policies. Please remove this piece immediately or I will have to report you.
You are violating the ToS and rules you agreed to follow when you joined DA. In case you were not aware, what you have been doing is considered art theft and is frowned upon.
It is a violation of DA policy to take images from the net, or any image that was not made by you and edit it and post it. DA only allows you to post art you made yourself, none of it can be from another person unless you have proof of the permission from the original artist.