I'm an idiot, as I'm rereading Prydain now. I like this book but the whole cauldron isn't just harkening back to that series, like I initially thought, it straight up feels like theft. I was heavily reminded of Prydain, and realise it's a huge influence on Maas, but reading this and The Black Cauldron so close together, one can't help but think, this totally ripped that novel off. In fact, the whole cauldron bit made me decide to reread Prydain because it reminded me of it. I just didn't realise how much it owes to that series.