So, does it have a happy ending? The short answer is:
Here’s an interesting, spoiler-light review that answers the question: Does “Revenge of Others” have a happy ending? does revenge of others have a happy ending
The show delivers justice — but justice in Revenge of Others isn’t rainbows and group hugs. Bad people face consequences. Secrets explode. The truth finally crawls into the light. Chan-mi gets answers. Soo-heon makes a choice that will leave you staring at your screen for a full minute. If your definition of “happy” is everyone lives happily ever after , you’ll be disappointed. Several characters are permanently broken. Others are gone. The final shot is poignant, not playful. So, does it have a happy ending
If you’re looking for a finale that ties up loose ends and lets the protagonists breathe a sigh of relief, you’ll be happy with how this one ends. Bad people face consequences
The primary source of "happiness" in the finale is the resolution of the murder mystery. We finally see the mask fall off the true antagonist, Gi Oh-sung. While the path to catching him is paved with trauma, the ending ensures he can no longer hide behind his father's influence or his own manipulative games.