Gene is well-known for cashing in at every possible opportunity, and Kubo for trolling his own fanbase. Kubo needed publicity for Bleach to remind fans that had drifted away during the Loads And Loads Of Filler that it still exists and maybe get some new readers too. Gene was looking for publicity for the new season of Gene Simmons Family Jewels and also on general principles. Between them, they conspired to replace Nick's reasonably-original-in-a Tropes Are Not Bad way work with obvious tracings, possibly done by Kubo himself. That's why Nick is so clueless as to ask for an apology and not have taken "...you will pay. In cash." down from his Deviant ART page - he wasn't in on it. (Note that this means he's so clueless as to have not inspected a final published copy of his own book.)