In "Die All, Die Merrily" we get an action packed episode, almost plot free, where "The 100" offers the fans lots of actions and a "Battle Royale" or "Hunger Games" kind of environment: a fighting arena and only one can survive.
How does it fare? Well, it does a great job. It has nice action set pieces, a couple of nice twists (and a great one) within the set up, and lots of bloody moments. We get Octavia, Roan, Luna and many many extras fighting against each other, all for their own clan, except Luna who just wants to win to stop anyone from surviving. Cue heads rolling.
All the fans will enjoy this Octavia centered episode, the action scenes and the desperation of the characters, all fighting for their loved ones survival. And if Luna wins, no one survives.