Mixed feeling about this, the only thing I hate is a Deus Ex Machine, and so far it seems heading that way. I know that I can't expect such a dark theme from a series that started so light but chapters 5 and 6.
I mean the end of chapter 5 was brutal and the ending of 6 was even better, as yukari saying "I will not forgive you" while remenbering the death of yuyuko was beautiful. I was actually hoping for the "I know this will end up badly" explanation from yukari side or even a mere jealousy case because reimu had what she couldn't would have been very acceptable justifications for her actions.
I really hope that this doesnt end up as:
"they drank a cup of tea afterwards, and lived happily for the rest of their life"
Yukari, I will let you know one thing. No matter what, the power of love triumphs everything, when you truly love someone you will do anything for them regardless of the consequence