This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Scrapped Princess
Where do I even begin with this one? Lets see now: Pacifica, Cz, the Queen, Zefiris, Furet... The list goes on and on.
Expect one at least every other episode. The show is basically a series of emotional sucker punches with occasional patches of awesome.
Furet's death made this troper the saddest she's ever been in a long time. The way he was crawling on the streets while it was raining, while thinking he must not die, with the beautiful montage of all the sweet moments he had with Pacifica flashing... simply heartbreaking.
Add onto the fact that Pacifica's mother dies at the end of the episode, and her last request is Pacifica's name, so she can finally know her daughter's name. Pacifica yells back "Pamela!" Which is the name that Furet gave her, and that is the last thing her mother hears before she dies. Take your pick about what is more tragic—a mother dying without seeing her child's face who's in the cell RIGHT NEXT TO HER, the child never knowing that she was her mother, or that the mother never actually knew Pacifica's real name before she died. Either way, it's tragic beyond no end.
Then there is Pacifica's long lost brother STABBING Pacifica in the back and killing her as soon as they meet for the first time before killing himself as atonement. Winia screaming "NO!!" just makes it worse. Of course the Reset Button is pushed in the end but it doesn't take away from the sadness.
If watching Raquel who, up to that point, had been eternally supportive and optimistic, fall apart when it happens, even going so far as to pray to Mauser, who wanted her sister dead, beseeching her to forgive Pacifica and spare her life, doesn't move you to tears, the sight of her desperately trying to hold onto her as she Disappears Into Light will.