Zee revealing his true form to scare off the Selkie.
Samuel threatening the Grey Lords.
Samuel: My father raised Mercy in his own pack, and he couldn't love her more if she were his own daughter. For Mercy, he'd declare open war on the fae, and damned be the consequences.
Meek, gentle Anna slipping a knife between Dana Shea's ribs.
No was the wrong answer, Anna informed her.
The whole sequence of events after Henry tricks Paul into challenging an injured Adam:
Mary Jo stepping in and using a technicality to force Paul to defeat her before he can fight Adam. Bonus points because she was fighting injured.
Adam fighting and defeating Paul despite not being in great shape himself...and then pointing out that for Adam, the advantage that Mary Jo gave him didn't allow him to win; he'd have done that anyway. It allowed him to take his time winning until he could do it without inflicting lethal damage. Knowing Adam, it's entirely believable.
Mercy shooting Henry in the throat (non-fatally) before he can finish issuing a challenge to an exhausted and injured Adam.
Offscreen Moment of Awesome: Warren, still not entirely recovered from being literally beaten to a pulp by a demon-vampire hybrid, wipes the floor with Paul during a challenge fight.
Agent Armstrong thought he was sitting between some weird young guy and a nice, big dog. Mercy soon corrects him: both Ben and Asil are werewolves.