Erik's life. Born deformed and out of wedlock (his deformation is caused by Belladova taking an abortifacient that failed), he is forced to live beneath the Opera House. The only person in the world (before Christine came along) who openly loved him and considered him beautiful is his mother, Belladova, and then she dies of an unspecified cause. He finds love (which is reciprocated) in his pupil, Christine, but the sight of his face drives her away screaming (Takarazuka) or causes her to faint (original). He is killed by his own father (granted, at Erik's request to be killed rather than captured).
The wailing meltdown Nozomi Fuuto's Erik goes through after Christine has run off. In addition to his heartwrenching cries, he rips off a fabric covering a wall of roses (a set from the Opera) and is faced with the fact that Christine - he believes - does not love him as much as Belladova ever did. He is reduced to sobbing on all fours in front of his mother's portrait.
Erik's death. Other Phantoms only calls Carrière by his first name and urges Gerard to shoot quickly. Nozomi Fuuto's Erik (in addition to crying out repeatedly and loudly in pain as he's being apprehended) screams at Carrière, calling him tousan/toosan. It's less polite than "otousan", and, roughly, translates to "Daddy!/Papa!" rather than "Father!"
Christine unmasking the Phantom herself, no longer fearful of his deformation, and kissing him gently on the forehead. This is the last act of kindness he receives before he dies. After his funeral, she sings a reprise of "Hear My Tragic Tale" with heartwrenching lyrics and in a distant tone, numb with grief. Turn on the sound when Christine plays their little leitmotif ("Do re mi fa so fa re fa mi...") in Erik's home, and you can hear Maaya Kiho's muted sobbing/hitched breaths as Christine tries to sing the melody almost inaudibly.