Etemon
Etemon first showed up as a serious threat when the Chosen Children arrived on the Server Continent, making it one of their earliest major battles. What made it dangerous wasn't just raw power—it had the Dark Network set up across its territory, giving it the ability to spy on basically everything happening in the area.
In Xros Wars, some Etemon units worked under Musyamon over in the Shinobi Zone. They'd disguise themselves as Shoutmon fans to hunt for Code Crowns, playing the long game to get what they needed.
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