He can make something based off of Through the Looking Glass, but he can't make something called American McGee's Alice or use any established characters from that IP.
Realistically he should just switch to another public domain fantasy. Kickstart "American McGee's Oz".
He can make something based off of Through the Looking Glass
And he should. Give the characters a dye job, spell their names different, and have at it.
![American McGee says they were "emotionally quite destroyed" by EA canceling Alice Asylum, and now they can't touch the IP "for the rest of [their] life](https://sh.itjust.works/pictrs/image/6b8b897a-7440-436a-a90a-e667f5a92d4c.webp?format=jpg&thumbnail=256)
He can make something based off of Through the Looking Glass, but he can't make something called American McGee's Alice or use any established characters from that IP.
Realistically he should just switch to another public domain fantasy. Kickstart "American McGee's Oz".
And he should. Give the characters a dye job, spell their names different, and have at it.