妖怪になっても一緒にいれたらいいよね、多分無理だけど

メリーの妖怪化が避けれない場合、蓮子＋メリー=紫説が一番二人にとって幸せな末路なのかもしれない
よくわからないね ちゅっちゅ

It would be nice if they could be together even if they become youkai, though that's probably impossible.

If Merry's transformation into a youkai is unavoidable, then the theory that Renko + Merry = Yukari might be the happiest ending for the two of them.
I don't really know though *chuuchuu*