What is, in your opinion, a grossly underrated Fantasy book?

When I first read Raybearer by Jordan Ifueko, I was surprised by how few people know about it. It quickly became my favourite fantasy book of all time and I’m genuinely afraid I will never read something as good again (barring Redemptor?). Anyway, what are books that you think so highly of?

(Another underrated book that NEEDS more attention imo is The House in the Cerulean Sea by TJ Klune).