That hat has also been recolored, edited, and reused by multiple other guilds(because the hat was an Anbu edit). He simply did what everyone else did and he was asked to do it.
Again, targeting a specific person for something that is so widely done doesn't really help the problem.
The guy you claim he stole it from literally has (Anbu Edit) in his original file for the mask - why is he allowed to edit something but yet the other person isn't?
You can't blame him for thinking it was alright to do what he did because it's happened so much and a lot of guilds have already done it.
It's just Graal and I think too many people over react over stuff like this, if people want to file personal copyright complaints against GraalDepot then they should do that nobody is stopping them.