Looks very good for your signature attempt!
I understand it is different having to deal with a much bigger image rather than avatars.
If I may give some feedback:
+ I've already mentioned it to you that your avatar style would definitely catch eyes if it was made as signatures, and I was right! Looks fantastic!
+ Your Rias Gremory background is very eye appealing!
+ Your choice of using other languages besides English is very creative.
- I suggest working on blending the character image with the background so that it looks more of a one whole picture rather than making it obvious that it's two different pictures placed on top one another~
- Your text outlines slightly seem a little "rough" and "choppy", maybe increase the shade and decrease the intensity of the outline glows!
- The shadow on the bottom right of the signatures are chopped off due to the boundaries! I also noticed the white outline around the signature. Rather than saving the image files as .jpg, save the images as .png!
Good work!