There will be a Guard ghost haunting the cult. It isn't HIM tho. Like it is not his soul. It is made of the grief and trauma that the cult experienced because of him

And, very importantly, it is made of their guilt and denial that they fucked up young Guard and keeps getting stronger as they keep making him into a scary story to keep kittens in line.

The ghost will haunt Aarre a lot as he lives in the shadow of his brother, not knowing what actually made Guard to what he became.

Suncat however is barely remembered by the cult, she is mostly mentioned as "the suncat of that one guard".