Q. I can't find criticism of William Blake's works in EBSCO, can you help?

There are quite a few articles on Blake's works in EBSCO. One thing that might help is to search all EBSCO literature related databases at the same time. You can do that from the All Literature databases page in Working with Literature guide or the Literature page in databases guide (links below): select All EBSCO Literature databases.

Don't forget to also try Literary Sources (also available from the links below). There are quite a few articles on Blake's works there as well.