deep-seated grudge; hatred
彼の怨念は死後も消えなかったと伝えられる。
It is said that his deep-seated grudge did not disappear even after death.
怨念が祟りとなって現れるという伝説がある。
There is a legend that a deep grudge manifests as a curse.
裏切られた怨念を胸に秘めて生き続けた。
He continued to live harboring the deep grudge of being betrayed.