This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Anti-Cliché and Mary-Sue Elimination Society
Adrian's Final Speech letter to Tash left in the Codex of Index is KING of this. My god. It's addressed to everyone he cared about and was close enough to...and reflects on the things he'll never get to do, in a sense.
Rhia's death shocked many to the point of this.
Adrian telling the story of his past to Tash. (That is...until it turns out to be false.)
Willowe reconciling with Adrian reveals there are Tear Jerker-worth moments here.
Part of the end of season 2. Divinity sends the entire Library into stasis in Development Hell after the entire Society suffered a colossalCurb-Stomp Battle at her hands in the Star Wars fandom. Harriet, Emily, and a heavily wounded Adrian manage to escape by the skin of their teeth, but are forced to spend the next two years alone on the run from her while trying to figure out how to free the Library.