When everyone finally stopped laughing, Rias managed to find her voice before Mako could go into another insane rant due to misunderstanding. "It's not that sort of Master relationship," she said firmly as she rubbed her forehead, trying to hide her wince. "It's...more like a shogun and a samurai."

Mako blinked and tilted her head slowly to stare at Rias. "...oro?" she asked in confusion.

"A...warrior that serves me?" Rias suggested awkwardly, hoping to get through to her. "Like a-"

"A servant?" Mako gasped as her hands flew to her face and a spotlight switched on from nowhere as she reached into the shadows. "You mean my-"

"Like a martial arts teacher!" Rias interrupted quickly before Mako could go off on whatever weird tangent she was about to go on. She'd already seen the 'slave' outfit, and wasn't really looking forward to whatever else Mako might pull out as she misinterpreted 'servant' in a sexual or otherwise manner.

Mako blinked a few times. "But what could you teach Ryuko-chan about fighting?" she asked plaintively.

"Umm..." Rias began carefully. "Uh...about being a Devil now?"

"Oh!" Mako declared as she smacked her fist into her palm. "That makes sense! ...what's a Devil?"

Rias sighed ruefully. This would probably be a rather awkward discussion. "A Devil is an unholy being spawned from the dark magic of Hell, seen as a blight on God's plan-"

A sudden clack and the sound of a choir that put heaven to shame interrupted Rias' speech as Satsuki's heel struck the ground, a brilliant light shining from behind her. "She did not ask for the hypocritical propaganda religion has fed the sheep in human clothing called 'the faithful'!" she snapped out intensely. "She asked you, a Devil that is of nobility, for the Truth that you know beyond what can be expressed in words!"

Rias found herself staring in awe. The light...it felt sacred, or holy, but it did not hurt to be bathed in it. For all the power that seemed to echo within it, and the strength of faith within it, it was a purely human light...the light of inspiration, of valor, of leadership. This was a light that could rally the masses of humanity to make war on God himself. She began to get a glimmering of how a 'mere human' could sway loyalty from beings far beyond human that defied description.

"Speak the truth from your heart that does not consult the mind!" Satsuki ordered, her voice a firm declaration. "What is a Devil?!"

Rias felt her spine straighten of its own accord as the words leapt from her heart and out her mouth before she could think. "A Devil is a being of magic that derives its power from the demi-plane of magic known as Hell, with an extended lifespan relative to humanity, the ability to use magic derived from that demi-plane, and an inherent vulnerability to the light powers wielded by Angels, their equals and opposites! There is no inherent superiority to Angels, Fallen Angels, Devils, or Humans, only the worth an individual demonstrates!" Rias blinked, stunned that through sheer force of personality and will Satsuki had made her snap to attention and speak a deep secret view she'd never spoken clearly - even to herself - without even thinking. Managing to relax, she rubbed her hand nervously. "...QED..." she murmured nervously.

Satsuki smirked as she relaxed, the light and music fading as she sat back down.

"Looks like you've still got it, sis," Ryuko teased playfully as she flopped into an easy chair, stretching out before wrapping her arms around Mako who - as expected - had plopped herself into Ryuko's lap for snuggles as soon as she was down.

"As if there was reason to doubt," Satsuki sniped back in an aloof tone.

"So why do you need Ryuko-chan?" Mako asked curiously. "Or any Devil Servants, for that matter?"

Rias sighed softly. However, before she could speak, Houka's jacket snapped open. "Given what was said about Devil's having a prolonged lifespan, it can be presumed that their reproductive cycle is either much longer or more difficult to accomplish than humans, and as such they have a much more difficult time replenishing their numbers as a species," he deduced thoughtfully. "Given the mention of Rias' group and a Fallen Angel having an interest in Ryuko, it can be presumed that there was some sort of conflict at some point in the past between Devils and Fallen Angels...and the mention of Angels suggests they were involved as well." He idly pushed his glasses up his nose before continuing. "A war of that scale likely would have drastically reduced populations on all sides. I imagine turning humans into 'Devil Servants' - and eventually into full fledged Devils in their own rights, presumably - is one of the ways they've developed to replenish their numbers. Likely, what noble lines remain are very careful to ensure they continue to exist in strength as well."

Rias was staring at Houka in shock through most of his speech. At the mention of the noble lines, however, she frowned and glanced away irritably. "You've gathered quite an effective group, Satsuki-san," she observed calmly. "I'm almost afraid to see what the rest of your team is-"

"How much of an asshole is the guy your parents have you engaged to, how much wiggle room do you have, and how many pieces would you like to see him in?" Uzu interrupted incisively, calmly polishing his bamboo sword.

At first, Rias was going to shrug off his bluster, but then she noticed the way the sword glowed to her vision when he gripped the handle. When he imbued his own energy into the blade, it took on sacred qualities. While it alone probably wouldn't do much against...him...it showed her that Uzu wasn't as helpless on the Devil scale as she'd first thought. "I appreciate the offer, but I don't think wood would do any good against him," she allowed sadly. "Too flammable." Uzu let out a derisive 'tsk', but said nothing...though the interchange did make Nonon giggle.

"So what happens if you two fight?" Mako asked curiously, glancing from Rias to Satsuki. "Who does Ryuko-chan side with?"

Rias hesitated. Despite Ryuko now being her 'Devil Servant', she'd already made it plain that part of the 'contract' that made that happen was that it not interfere with her life outside it, which plainly included her family here. If her family interests clashed with Satsuki's, she wasn't sure where Ryuko's loyalty should be expected.

"Then I punch her in the face," Ryuko offered easily with a cheeky grin.

"Her who?" Mako asked eagerly.

"Whichever of them's being a bitch and causing the problem!" Ryuko answered as her grin went even wider.

"But what if it's just a mutual clash?" Mr. Mankanshoku asked curiously.

"Then both until they compromise!"

Satsuki chuckled softly. "It appears your 'family' and mine are...allies now, whether we like it or not."

Rias sighed as she rubbed her forehead. "So it would seem. Is Ryuko always this much trouble?"

"This is one of the easier days," Satsuki replied readily with a small smirk.

Rias groaned as she took a seat, ignoring Ryuko blowing a raspberry at her sister. "Well, as long as you're piling on the headaches, perhaps you could explain Ryuko to me?" At Satsuki's raised eyebrow, Rias elaborated. "The...fibers?"

Satsuki leaned back. "Ah, yes," she allowed calmly. "That is a story and a half..."