Great artwork overall for your channel. For your banner, the blue text on the blue background might be a little conflicting. Thumbnails, you can consider adding some sort of branding into your work, or adding text to make it pop out more.. Your channel is already working well, and I feel that all you need is a little time, and getting discovered.
As an anime fan i really like the banner and thumbnails you use for the video's.
As mentioned above i would slightly adjust the txt color of the banner as it is difficult to read due to the background.