Annoying Arrows: Averted. One takes out Ilian when it strikes him in the neck.
Anyone Can Die: While the episode was set up as a fight to the death, no one expected Roan to die this episode.
Roan, Luna, and Ilian all died this episode. To be more specific, Ilian gets shot in the neck with an arrow by Echo and is mercy-killed by Octavia, Luna drowns Roan in a nearby fountain after the black rain starts falling and finally, Luna herself is stabbed In the Back by Octavia using Indra's sword.
Chekhov's Gun: Before the Final Conclave starts Kane warns Octavia of the possibility of the black rain and warns her to find cover if that happens. Sure enough in the final stages of the battle it begins raining which allows Luna to get the upper hand.
Chekhov's Skill: Under Bellamy's suggestion Octavia uses her survival instincts as the "girl under the floor" to directly avoid confrontation and ends up killing Luna with a misdirection wining her the battle.
Diabolus ex Machina: Roan and Octavia have Luna on the ropes...and then the acid rain (which only Luna is immune to) starts to fall.
The Exile: After finding out that Echo has been killing his competitors behind his back Roan orders her to leave and never return. He also makes it clear that, if her wins, she wont be one of the people he saves.
I Am Not My Father: Well, mother. Roan cites this as why he won't allow Echo to cheat for him during the conclave as he doesn't want to win with dishonor.
Kidnapped by an Ally: It's revealed that Jaha and Clarke had Bellamy drugged and kidnapped to get him out of Polis and into the bunker.
Mercy Kill: After Ilian is hit in the neck by one of Echo's arrows he begs Octavia to kill him to end his suffering. She does so after giving him some passing rites.
Motive Rant: After killing Roan, Luna goes on a rant on how saving the human race is futile and how they should all die.
Parental Substitute: While it's been heavily implied before, this episode pretty much solidifies that both Kane and Indra are this to Octavia. Indra even gives Octavia her sword, which she says her own daughter would never accept.
Shut Up, Hannibal!: After hearing Luna give her Motive Rant about why she no longer believes in people and misdirecting her into believing that she is hiding in one of the cupboards Octavia stabs Luna and tells her that she is wrong and that their are people worth saving. Luna just isn't one of them.
So Proud of You: After Octavia declares that the remaining twelve clans will share the bunker evenly and become one Indra tells her that Lincoln would be proud of her.
Straw Nihilist: Luna has become this as of this episode thanks to being experimented on by Skaikru and no longer believes that humanity is worth saving to the point that she wants to win the Conclave to specifically ensure that nobody can use it.
Wham Episode: Roan, Luna, and Ilian are killed, Octavia declares that all of the clans will share the bunker equally, and Skaikru forcibly takes the bunker while the other clans are distracted by the conclave. Oh, and it was Clarke's idea.
