This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / The Dalemark Quartet
Mitt realizing that Alis his father, that they are Not So Different at being jerks, and that Al hates him for messing up the initial assassination plot. After this, Mitt decides to become a better person instead of becoming Al.
The Crown of Dalemark
It turns out that one of Maewen's mentors is Duck from the previous book, and he had asked her to impersonate his daughter Noreth who is a potential new leader. When he finds out that Noreth has died on her crusade, he lashes out at Maewen even though she says she was only doing what he ordered her to do. Eventually he breaks down crying.
Going on from this, a minor Tear Jerker when Mitt and Maewen encounter Cynnoreth. Given that "Noreth" is a diminutive of "Cyynoreth," Duck named his daughter after his sister.
Maewen returns to the present and learns that Mitt died and was buried in the mausoleum right outside her window.