Sorry but i couldn’t come up with a clever title, but anyyyway don’t mind me retconning a lot of my characters. These are the children of the sirens first introduced here  
Bad End AU: Sirens Legacy. by BunnAri  
but i decided to change some things (for now at least)
 
Requiem Rallentando is now the son of Adagio Dazzle and Nightmare Moon instead of Stygian. Born from a one night stand between them before Nightmare had any children with Twilight. He isn’t recognized as Nightmare’s heir and even if he doesn’t act like it, the fact infuriates him.
 
Rhapsody Allegreza is the daughter of Adagio Dazzle and Sapphire Shores (decided to scrap Coloratura and Svengallop because i want to use them for something else in the AU). Life of the party. extremely spoiled and likes to use her voice to scare others.
 
Vaporwave Koi and Crescendo Profundo are the children of Aria Blaze, Vinyl Scratch (Vaporwave Koi, short relationship) and Moonlight Raven (Crescendo Profundo, current partner). Vaporwave does most of the talking, Crescendo intimidates.
 
Stark Echo is the son of Sonata Dusk and princess Skystar. The sirens eventually found seaquestria and conquered it, giving Skystar to Sonata as a “prize”, in reality it was so Adagio and Aria could manipulate the reign through Sonata. Echo is seen as an outcast by the seaponies, after all he is part of the ones that destroyed their peace again.