Mysterious Invaders is the fifteenth chapter in Kid Icarus: Uprising and the beginning of the Aurum mini-arc, where Pit fights off new and mysterious off-worlder foes. The invasion takes place on a huge continent-like base, home to the mysterious Aurum. Pit must to defeat these new enemies and protect Angel Land.
This mission starts off as Pit slowly jumps out of the door because he was woken up early. Palutena informs Pit of the recent invasion of the mysterious, alien-like enemies. She informs the angel that the creatures are harvesting the Earth and its inhabitants. Meanwhile, Viridi and Hades had been fighting, and if the enemies never invaded, they both claimed they would've finished off each other. Hades asks Palutena if she knows anything about the enemies, but all she replies is that they aren't from this world. Knowing how dangerous this new threat is, Palutena's Army, the Underworld Army and the Forces of Nature form a temporary alliance in order to fight off the invaders. After fighting off the invasion for a while, the Sun God, Pyrrhon, comes to the scene and helps Pit fight the enemies. Pyrrhon apparently knows these extraterrestrial beings, and he says they are known as the Aurum, an alien race that invades wherever and whenever there is massive destruction and war. Palutena looks at Hades and Viridi, rightfully hinting blame to them because of their deadly war. Viridi stands up for herself and says that everyone is a victim, and Palutena agrees, saying that they all are on the same side. Pit infiltrates the huge colony so that the Aurum won't eat the world, leaving Pyrrhon to help out as well.
Pit lands on an Aurum Island, the one controlling the Aurum on the first invasion. Fighting enemies along the way, Pit makes his way inside the main tower. Inside, Pit finds a Mimicutie and a moving Hot Spring. Palutena tells Pit that he can get to the Hot Spring if he goes up a floor. Viridi isn't sure if it's a Hot Spring or another type of puddle. Outside, Pit finds an Exo Tank, which everyone is confused about. In the next room, there is a jump and another Exo Tank. If Pit tries to jump the gap, Viridi tries to psych him out by yelling, "You're gonna fall! You're gonna fall!". After using the Exo Tank to go down a spiraling path, he will find another Mimicutie. Pit then goes up an elevator to a place with a grind rail. Palutena says that when she was setting up the grind rail, it got distorted and turned out weird. Viridi is annoyed with the Aurum for messing with her godly powers. After Pit rides all the grind rails and goes down the elevator, he gets to a place where he can traverse down into the tower. Pit then goes down the elevator to the first boss of the mini-arc, the Aurum Core.
The Aurum Core doesn't physically attack, but it controls electric floors and laser drones to shock and blast Pit. The Core also has three rotating, orange-plated shields protecting it. If shot at, Pit's fire returns to him. In between the shields are gaps which reveal the weak-spot of the Core. This must be hit with ranged attacks to destroy the whole island. As the Core takes damage, it starts to activate more dangerous defense systems, such as a vacuum to suck Pit closer and large explosives, making the fight increasingly dangerous.
- Reflect Barriers: The Aurum Core is outfitted with rotating shields that will reflect Pit's shots.
- Laser Turret: The Aurum Core is outfitted with laser turrets surrounding it and along the walls of the room that shoot lasers at Pit.
- Electric Floor: Parts of the floor will electrify itself, damaging Pit if he steps on it.
- Vacuum: After taking enough damage, an alarm will sound and the Core will try to suck Pit close to it.
- Bombs: When the Core is on its last legs, bombs will appear throughout the room, damaging Pit on contact.
After the Aurum Core is defeated, Pyrrhon saves Pit from the explosion caused by the destruction. Pit is extracted by Palutena, while Pyrrhon senses future danger. He turns around with the chapter ending by him witnessing the invading Aurum Fleet and teleporting away.
- Though Palutena doesn't know much about the enemies, she still knows their names.
- During the Land Battle, Hades may randomly ask Pit why he can't fly. Palutena answers for him by telling Hades that Pit's wings don't work properly. This may confirm the reason why Pit can't fly.
- The Exo Tank in this chapter was likely placed by Viridi as Palutena explicitly states it wasn't her doing, and it would be unlikely for Hades to help Pit. The Aurum arc is also where Viridi noticeably softens up to Pit, and her overall defensive attitude raises further suspicion. The same likely applies to the Aether Ring and hearts in the next chapter.