Eldritch Tamers Go!
Yuji’s “Maglia” is a mistake — created by an error with the Trading Machine when Yuji’s was trying to trade a Ralts he’d caught for Bill’s Magnemite. This mistake sparked Yuji’s life-long interest in researching the possibility of deliberate Pokémon Fusions and lead to the eventual creation of the Fusion Machine.
Despite significant improvements to the fusion technology, and several other successful (intentional) tests, Maglia remains Yuji’s closest companion. Unlike deliberate fusions, Maglia is unique in that she adopted the secondary typing of her constituent pokemon, making her a Steel and Fairy type rather than the Electric and Psychic results of all future attempts at fusing these particular species.
Yuji: "Hey, would you like to see an actual Fusion? Tell you what, I’m almost done with the upgrades to the pokemon trading machine. If you can beat my Maglia, then I will give you beta access to use the Fusion machine at the pokemon center.
Woh! You beat her. I’ll tell Nurse Joy to let you use the Fusion Machine prototype. Just remember, that once you have fused two pokemon, there is no way to un-fuse them…"