Poison

"You picked your poison I chose mine, and it's you." She said softly looking into his eyes stubornlly.

"Poisons are called deadly for a reason," He said gruffly.

"Well I'm ready to die," she spoke softly fearing speaking louder would breack the spell he has on her.

poi·son
ˈpoiz(ə)n/
noun

a substance that is capable of causing the illness or death of a living organism when introduced or absorbed.
synonyms: toxin, toxicant, venom; archaicbane
"a deadly poison"
verb

administer poison to (a person or animal), either deliberately or accidentally.