それから、最後の恐ろしい叫び声とともに、怪物は山から下方の岩に身を投げて死んだ。
Then, with a final, terrible scream, the monster flung itself off the mountain to its death on the rocks below.

果報は寝て待て。
Everything comes to those who wait.

できることはすべてやったよ。後は、果報は寝て待て、の心境だね。
I feel like I've done all I can. Now all there is to do is wait and see what comes of it.