
You asked for a major spoiler so here it goes:
Amon is a dragon and Nain is his mate. The mate has to be swallowed and remade by the dragon’s magic to be immortal. However, depression is lethal for dragon’s mate - they literally dissipate into nothingness. Nain almost died when the child he took in and raised died. Since Amon didn’t know how to soothe him, he completely wiped his memory by the incense. He also ordered for Nain to get used to death so it wouldn’t happen again - that’s why the sacrifices. However, the incense must be done repeatedly or the memories will resurface.

Think of it like this:
Amon is sleeping peaceful. Not doing anything.
Nain storms in, crying and screaming "HOW COULD YOU DO THIS?!"
Amon, confused and trying to handle the situation, give blunt responses as a way to (potentially) help calm Nain.
Nain is afraid and depressed and demands space from Amon while also telling him not to look at anyone else.
Amon obliges and lays alone waiting for Nain.
Nain lays alone waiting for Amon.
Then Gwen
From all the spoilers I’ve been reading there’s a reason for this abuse….unless he’s trying to awaken something from Nia …(but that would negate the brainwashing bs) ughhhhhh i still don’t like it like even what the flashbacks are showing like..bruh unless Amon is js emotionally dead(honestly he might since he calls humans ants lol) but the nigga has eyes even the servants know that Nia hates blood like I don’t fucking get his thought process I still stand by it torture is torture what ever love story they had in the past don’t justify it ugh I’m done yapping let the plot defend its self ig also someone drop major spoilers for me pls