I had a feeling it was sort of a turbo granny sitution going on with him but its nice to confirm. Yasaka was a being consumed by malious and curses it can't be helped given what happened. But his true purpose still lay in keeping his promise to Tomoe enshuring that another "her" would not be born. He kept that promise in the end. Thanks to him, Koharu rose above her fate and personally slaughtered her oppressors.
I wouldn't be surprised if where villagers attacked Koharu is the same place where Yasaka swallowed Tomoe. Adding extra weight.
Regardless I'm sure one day Dara-san and Mr. Snake will have a proper conversation about their past in the future. Maybe over a few cups of sake. (also Dara laughing at him about his gotcha like like dang dude.)