Hsi Wu frowned to himself as he tailed the Chans back to their base as discreetly as he could manage. While he could have done so openly as long as he kept his magical energy somewhat suppressed thanks to the Veil, he didn't want to risk being spotted by the Chans. While he was as clever as any of his siblings, being among the youngest - and a born demon at that - meant that he had the smallest magical reserves, and relied far more on his elemental connection than any of his siblings save Bai Tza. The fact that said element was literally everywhere one could breathe helped make him more durable and helped him draw extra power from his surroundings...the higher he was, the better.
Still, the world had changed. Humanity now climbed much higher into his domain, and other magic had followed. He had to be careful, and expend as little of his own reserves as possible. It's why he was so creative with how he used his magic, since he more than any of his siblings had to do the most with as little as possible. This led him to push the limits of magic, ignoring the rules of 'this is how it works' to understand why it worked that way. It was why, given what he'd seen of the world from the Demon Netherrealm, the first thing he intended to do as soon as he had his tail and full freedom was to raid a library for science textbooks. He was especially interested in the subjects of chemistry and gas formations.
First, however, he needed to retrieve his tail. Landing on the building across the street from the Chans' base, he watched through the window as Jade - under the instructions of the three fillies - managed to wrangle the tail into a chest, at which point the old wizard laid a protective spell upon it. Using a very small amount of his own magic, Hsi Wu enchanted the local wind currents to carry sound better. Between that and his large ears, he was able to hear every word said clearly.
"So now what, Uncle?" Jade asked curiously. "Got some trick with the tail to deal with Hsi Wu? Some special plan to trap him?"
"I have a very good plan," Uncle responded calmly. "Uncle plans to prepare for the next demon."
"What?" Apple Bloom - Hsi Wu recognized the voices he'd heard through the restroom door before - demanded, shocked. "What do ya mean?"
"Valmont move fast!" Uncle insisted. "Hsi Wu is free now, but not causing ruckus. Either peaceful, or tricky. If peaceful, can be ignored. If tricky, is good test for girls as Chi Wizards. Sky Demon is your responsibility, while I prepare for other demons."
"A-are you sure we can handle it?" Sweetie Belle asked worriedly.
"Uncle is certain," Uncle confirmed. "I have full confidence in you all."
"What if Hsi sneaks in?" Scootaloo asked curiously.
"Shop is protected!" Uncle insisted. "Bad magic cannot enter unless invited!"
Hsi Wu let his magic subside, returning the wind currents to normal. He'd have to be careful about the fillies, but the old man would regret leaving something so important to children. He needed to be invited in? Fine. He would get an invitation. And he already saw a way. Mortal children of powerful magic were always lonesome, and the adventures they were involved in would have left Jade and the fillies even more outsiders socially. All it would take would be the perfect opportunity, and the right strategy. Until both presented themselves, he would watch and wait.
The following day, Hsi Wu stared down at the school playground in glee. The perfect opportunity had dropped itself in his lap! The fillies were elsewhere, and Jade was being confronted by a glasses wearing boy with a large audience whose stance made it plain this was hazing waiting to happen.
"You going to the Spring Dance next week?" the boy began, his tone playful as an opening play, waiting for Jade to walk into a trap.
"Maybe," Jade countered. "What's it to you, Drew?"
Drew smirked as he lifted his hands in a facsimile of a fighting pose. "Who are you going to take? A ninja? Or do you just fight them?" The audience laughed as kids do, though not too strong. Given Jade's expression, Hsi Wu concluded this was a common taunt, probably from her being too free with stories of adventures.
Seeing his opportunity, Hsi Wu swooped down nearby, taking on a human form. His body was that of a child Jade's age, with features showing Chinese descent. His outfit was entirely green in different shades for pants, long sleeve undershirt, and short sleeve overshirt. His antennae blades shortened into a similarly shaped hairstyle, his hair black-blue and his eyes brown like his shoes. The look and outfit complete, he rushed in at just the right moment to deliver the telling rejoinder. "Who are you going to take to the dance, Drew? Your Mom?" Not the cleverest counter Hsi Wu could have delivered, but good for the target audience. Considering the laughter and Drew's stammered flailing, it accomplished its goal.
As the group dispersed, Jade turned to him. "Thanks for standing up for me." She frowned thoughtfully. "I don't think I've seen you around before."
"I'm new," Hsi responded immediately. "Just moved here."
"And you stuck yourself in the middle of something like this?" Jade asked, surprised.
Hsi shrugged. "Being in your shoes in things like this is why I moved," he responded, surprising himself. That hadn't been the cover story he'd planned...but it was somewhat accurate. On Earth, he could meet all his siblings as equals, if not as their betters due to how he used his magic. But in the Netherrealm, there was no Elemental energy to draw on, and only Tso Lan had access to his Elemental Magic due to its nature. As such, Tso Lan and Bai Tza were the only one of his siblings that didn't push him around while they were trapped there. Hsi privately suspected it was because they feared what he could do with his magic. The exceptions were because Tso Lan respected his mind, frequently engaging in various games of skill with him to pass the time, whereas Bai Tza...well, Hsi Wu and Tso Lan were the only human sized members of the Brotherhood besides Bai, leaving them the only options for her preferred games.
He pushed all that from his mind as Jade smiled, holding out her hand. "Well, us targets have to stick together. I'm Jade."
Hsi Wu immediately accepted the handshake. "Hs-" He cut himself off. He'd almost given her his true name. That would have been disastrous...and now he needed a new name starting with the same sound. "Seymour Jahoositz," he managed to spit out, wincing internally at how ridiculous it sounded.
To his surprise, Jade winced sympathetically. "Talk about unfortunate," she murmured under her breath.
Hsi decided it was time to change the subject. "So is it true?"
"Is what true?" Jade asked, confused.
"Do you really...fight ninjas?" Seeing the grin spreading across Jade's face, Hsi knew he'd hit on exactly the right approach. A girl like her craved an eager audience.