Maybe there is a misuderstanding : I didn't "just" bought the pack like anyone else on itch and reuploaded it on my account (this would be stealing, of course). No, instead I talked to my teammate Noiracide (the author, who works with me on this collection) and agreed with him that he doesn't want to keep this pack anymore. He doesn't plan to update it and prefers to focus on other works, which is understandable. So we made an exchange : I buy him the "rights" of this pack (which is way more expensive that the pack itself) and he removes it from itch. This makes me now the owner and responsible of this pack.
It is in "100% sale" instead of "free" to be able to add it to bundles (that's how itch works). This way, it's easier for users to find and claim, overwize they can miss it.
Of course I'll add more characters in the future, that the reason why I'm making all of this.
If you are still not happy with the situation, well that's a pity. My objective is to provide a complete collection of assets an be able to update them freely since none of my teammates wants to work on it anymore. Have a good day.