Twins of Lord Tirek and Rainbow Dash. Don’t know they got together exactly. I suppose they attempt to reform Tirek like they did Discord. But Fluttershy doesn’t work on him, so Rainbow takes up the challenge. They fight all the time but it turns to sex.
 
The twins, Sonic Cool and Awesome Rainboom. Sonic is the blue twin, who is a prank master and is something of a weirdo. She loves kissing people off and generally being a nuisance. She loves rain and causing unscheduled storms. Rainboom is a bombastic and positive guy, the very opposite of his father. He loves making people happy and loves flying and competition. He can actually make rainbows that can last for a few hours just by flying!