Well I've made some new signatures recently, curious for some comments, and I welcome criticism as long as it comes with a way to fix what is wrong. BTW Dream is my name on another forum, I did not rip these and claim them as my own work B&W: B&W
The first one was well done, can't say much about it. Second one, the colors are kinda bleargh, and the background is so unclear, it looks like an error on your part. The third one with Sora; pretty good, but kind of random. Interesting colors, but maybe you could blend it a tiny bit more? The color version are all better than b&w.
The first one needs more of a flow and a bit more depth. The second has crazy colors and is kind of going different ways in terms of flow. The third one take out the border. Also the spatter effect (I think that's what it is) should be lowered in opacity or taken out. This one also needs some more depth. All of them I say lose the text too, or keep practicing on it.