I’d say either [Conquest](Ryoma’s suicide in conquest) or [Shadows of Valentia](Berkut and Rinea’s deaths.) First of all [Birthright](Ryoma’s death was completely out of the blue. After defeating him in his chapter, he kills himself after learning of Corrin’s plan to defeat Garon, to make it seem as if Corrin doesn’t know about Garon’s goopy side. It was surprising because I personally didn’t expect any of the main characters to die in Fates.) Second, I have [SoV] (the deaths of Berkut and Rinea. The deaths of these two convey so much emotion in them. At that point in the game, Berkut had practically lost everything to Alm. His pride, his chance for the throne, and his mind. The only thing he has left is Rinea, but he only cares for destroying Alm. Alm has intoxicated his mind to the point where he’d sacrifice anything to kill Alm, including Rinea. Eventually, he sacrifices Rinea for Duma’s power as well as the spear Kreimhild, and Rinea becomes a witch made of fire. After Alm and company kill both of them, Rinea forgives Berkut and he realizes the horrible things he’d done out of jealousy and spite, and forgives Alm, and gives him the piece of the key he needs to get to Duma’s lair.)