*sigh*
You say that what I said is not true, but nothing you quoted there actually disproves anything I said.
Yes, they don't claim ownership of all of them, but they collected the images which were, as far as they're aware, made available for public use by the original authors. Furthermore, this library has been around since June 2015, and despite making it extremely easy for people to claim the images to get them removed, it hasn't happened.
If, as you and others have asserted, Akabur's images are
not public domain, then why hasn't Akabur done anything about this? Because he
has to be aware of this.
Also, as an example indicating he's OK with this, the "silver" edition of
Witch Trainer was made by people other than Akabur, using large portions of his work, but
You must be registered to see the links
("adminaka" = Akabur).
You have to go out of your way to ignore these facts to somehow come to the conclusion that they aren't public domain, as the page you quoted indicates.