Kiss of death
In the scene where the long haired guy killed the seductress, did he want to kiss her and see if he would die from her poisons? Or did her powers get to him and force him to kiss her?
shareShe didn't force him. He willingly took the kiss, knowing it would end his life. He knew the age of the Shinobi was to pass, so there is an honour with him ending his life as he took hers. It's poetic.
That's my take on it, anyway.