To be enemies with s.o., to have s.o. as an enemy; to treat s.o. as one’s enemy.
Enmity is usually the result of killing but it can occur for other reasons as well.
Magbanta si Toto' duk si Apa'.
Toto' and Apa' are enemies.
Even though they killed my relative I do not treat (them) as enemies.
I treat her as an enemy because she did not share the land with me.