Falcifer=False Lucifer
The two dragons arrived at the ORC club building and began to look around for any evidence of where whoever kidnapped Rias and the others could've taken them.
"Val, isn't your dad some kind of demonic detective didn't he teach you things?" asked Issei.
Vali said nothing just looked around her eyes glowing red, her hand rubbed over every surface as she walked by and got flashes of the scene, she witnessed someone fighting Rias and her peerage, they beat the group and dragged them off, Vali sat down her legs crossed.
The door then opened, "Issei, Vali," Yuuto Kiba called.
"Issei, what's Vali doing?" asked Gasper Vladi.
"I'm trying to get a read on the soul signature of whoever took Rias and the others, but I can't concentrate if you all are being too loud," Vali said annoyed.
"Come on guys let's go outside and I'll explain, it's never good when Vali's annoyed," said Issei and he lead the two outside.
"Ok Issei, what's happening?" asked Ravel Phenex.
"Me and Vali don't come from this universe, we come from another one, Valis father, Cain Blaze is currently likely trying to save us, or at the very least is unknowingly helping us if he has no memory of us by fighting a demon named Mephistopheles, or Mephisto for short, if me and Vali can find whoever's keeping us trapped here and find a way to escape at the right time that uncle Cain beats Mephisto, we might be able to free ourselves, we think whoever took Rias, and the others and replaced them with the fakes that were hanging off my idiot adopted brother might be connected to this," said Issei.
"Count us in," said Saji.
"Good we're going to need all the help we can get," said Vali as she walked out.
"Did you find them?" asked Issei.
"I did, and I know who took them, a demon my father fought often who claimed himself to be Lucifer, though if that were Lucifer, my father wouldn't be able to survive much less win a battle with him, as powerful as Zarathos is he's not on the same level of Lucifer Morningstar," said Vali
"Can you track him?" asked Issei.
"I'm a blaze, I can track any demons stench like a bloodhound," said Vali as she snapped her fingers and a motorcycle was summoned to her.
"Vali, we need to go as a group," said Issei.
"Huh, we'll be able to ride again soon my love," she said to the Motorcycle as it disappeared.
Vali activated a summoning circle and they appeared outside a warehouse, "Rias and the others are in there," said Vali.
"Then let's go," said Issei as he activated his boosted gear, Vali activated her divine dividing and summoned her fathers demon king daggers, everyone activated their sacred gears or abilities and went into the warehouse.
"Issei, Vali," Rias cried out.
"Rias," Issei called as he went over to her.
"Hahaha, so you finally show yourselves spider spawn and rider spawn," said a blond man as he landed in front of them.
"So your the false Lucifer," said Vali as she summoned a ball of light and blasted it at the pretender.
Falcifer just dodged the blast, "your father couldn't defeat me girl what makes you think you can?" asked Falcifer.
"Pretty sure the only reason your still alive is because Mephisto has to keep saving you not because my father couldn't ever beat you," said Vali as she attacked with her daggers.

DU LIEST GERADE
The Children of the Spider and Rider
FanfictionThe story of the children of Peter Parker, the Spider-Man, and Cain Blaze, the Shadow Rider. (couldn't find a good cover, nor can I make one, so have the Spider bros)