Armor-Piercing Question/Armor-Piercing Response: Scar gives both of these to the Elric Brothers when they confront him about the murders he's committed. When Al asks if he was doing God's work by killing Shou Tucker and Nina, Scar points out that alchemy is what turned Nina and Alexander into a tortured chimera and asks if that's really the science they ought to spend their lives following. While Ed does concede that point after a brief pause, he then angrily asks why Scar had to kill Nina, only for Scar to completely destroy whatever retort the brothers could come up with by pointing out that Nina and Alexander could never be separated again and the chimera would have to live the rest of its painful life as a laboratory specimen.
Bittersweet Ending: Winry finds out that Scar killed her parents, loses it and pulls a gun on Scar, debating whether she should shoot him or not. In addition, Scar's full backstory is revealed to the audience, detailing how he went from a good (albeit strict) family man to a broken one on a Roaring Rampage of Revenge after he lost his brother in the Ishvalan War of Extermination, thereby losing the last family he had left. However, Ed succeeds in convincing Winry not to go through with shooting Scar, comforts her as she breaks down crying for grief, and Scar begins to understand that his quest for revenge might not be worth it (though it's not until several episodes later that he fully understands and takes a different, healthier approach).
When Scar angrily condemns the Elric brothers for continuing to follow the path of alchemy despite knowing full well of its darker side, the brothers are both reminded of Shou Tucker.
Shou Tucker:(to Ed) Look at your brother; he's the result of "messing around with somebody's life".
Scar's Master's warning about the dangers of the Cycle of Revenge back in Episode 15 is replayed when Winry pulls a gun on Scar (i.e. the man who killed her parents).
Cycle of Revenge: Played for serious drama. For the first time in the series, Scar finally begins to get it. He finally begins to realize that his Master was right about becoming trapped in this cycle after encountering Winry (and realizing that he's symbolically become Kimblee after trying to attack Ed while he's protecting Winry).
Failed a Spot Check: Ed angrily calls out Scar for killing Winry's parents, not realizing that Winry is nearby and can hear everything. Al realizes and tries to alert Ed before it's too late, but to no avail.
Jerkass Has a Point: When Ed and Al confront Scar for killing the chimera made from Nina and Alexander, Scar immediately retorts that they of all people should know that the chimera could never be separated again and would be forced to live the rest of its life in agony as a laboratory test subject. The brothers silently admit that they knew what happened to Nina and Alexander is irreversible and they could never be returned to normal.
Ling Yao finds out that Führer Bradley isn't merely working with the homunculi; he is one of the homunculi.
Winry finally learns it was Scar who killed her parents.
Wham Shot: In-story instance when Ed reveals to Scar he's learned he killed the Rockbells... only to realize moments later that Winry was right behind Scar and heard it all.
