This story is a sequel to The Cuckoo Child
This story is a crossover between MLP and the Heroic AU of Alan Ituriel's Villainous, and takes place in the same time frame as The Cuckoo Child.
After Black Hat, a renowned villain known for mocking 'lesser' villains, made the mistake of sassing Discord in one of his videos, he found himself unceremoniously transformed into an infant changeling with no clear way home. However, after the initial smug satisfaction of completing his act of petty revenge, Discord realised that he'd effectively unleashed a potent force of evil into Equestria - something he doubted either the Princesses or Fluttershy would think well of.
Clearly, he had to do some kind of damage control - not exactly his forte, but he couldn't disappoint Fluttershy, not after the Tirek fiasco. Obviously, he had to balance this out - preferably in a way that would encourage chaos, of course. Perhaps an equal opposite? The nearest good-aligned alternate universe counterpart to the target of his ire was an admittedly uninvolved hero named White Hat, but while the draconequus had some scruples now, he wasn’t exactly totally reformed. Plucking this eldritch being from his bed to reformat into another changeling egg just seemed like the most effective solution to his problem, and that was exactly what he did.
Skipping back to the same time frame he'd left Black Hat in, he modified White Hat's egg to fit the specifications of the infirm Queen Setae’s last brood within the small hive in exile she’d dug under the Everfree. As an afterthought to encourage further chaos, he also, before departing, wove a magical bond between the eggs - a geas of sorts. When they met - and he was certain they would - they would have to work together. That ought to really put the wind up the uncouth excuse for a gentleman who'd insulted him!