Is it illegal to have a human skull as a chalice?

Occult means "hidden". It doesn't mean devils or Satan or evils, or black and white magic or anything like that.

I have no idea what faith or pagan tradition you're in, but I've never heard of one that would celebrate the idea of using another person's body for their own gain.

Not even Satanism would do that. Satanism is all about promotion of the self without harming anyone else. So unless you had the other person's permission (as in- "when I die, do use my skull as a chalice, eh? wot wot) it seems kinda pointless.

So, you probably don't know what you're talking about, or just want to look badass.

It would depend a great deal on how it was acquired and who's it actually was. Some individuals do donate their bodies to science and I do think that this is the only manor in which human remains can be owned legally.Beside the legal implications there is the moral implication. Though it may be legal to ultimately own body parts , is it not more a question of morality ?

No. Stalin had a fake "hitler" skull as trophee, but as tests prove it belongs to a black jewish woman several decades younger than Adolf Hitler.

So obviously Adolf lives, and no one cared that Stalin had a human skull as trophee or chalice.

It's personal property, once you have it.

I really don't know

but you doesn't posses this skull as it's a part of another person,

I think he wouldn't accept this if he was able to speak !

Legal. If you can make it into a talking skull - murrey.