Reisen Riou savored a mushroom, its earthy tang sparking his thoughts. "Holistic brain development can't match targeted," he told Bona. "If targeted development hits 100% efficiency for specific brain regions, holistic's maybe 1%, if that. The brain's zoned for different functions. I once toyed with prioritizing one region, treating others as secondary to save rare resources and lower maintenance costs. Sounds great, but Teyvat's tech can't pull it off. Brain regions are too similar; we can't pinpoint them precisely. My suggestion? Stimulate the target region with activity, then use drugs to boost development. Higher accuracy."
Bona stroked his beard, nodding. "Makes sense. The brain burns nutrients like plants draw from soil. Mix the drug into those nutrients, and you get targeted development."
"Exactly," Reisen Riou said. "Enough shop talk. Eat up. I'll prep detailed notes before you leave."
"How long you staying?" he asked.
"A few days revisiting old haunts," Bona replied.
A quarter through the mushroom feast, Raiden Makoto and the others left for Shogunate duties, set to enjoy their share at Tenshukaku. Bona, sipping fragrant mushroom broth, leaned in. "Your wife, Ei—what's her deal? She's got a sharp edge."
Reisen Riou grinned. "She's a martial leader in the Shogunate." True, though he omitted she was the martial pinnacle, Inazuma's swordsmanship source.
"A warrior, huh? Explains the aura. Her sister Makoto seems calmer, probably a high-ranking civil officer," Bona said, eyeing the steaming soup. The feast's slow pace was forgiven—fine work took time.
Reisen Riou nodded, amused. Bona's mortal eyes nailed their vibes but missed their divine truth. Best not scare the old man with their godhood; a heart attack would be tricky to fix. "You sure you don't want to meet Lady Makoto formally?" he asked.
"Nah, I'm retired," Bona waved off. "Just here to revisit old spots, see friends, and nudge my Vision research along."
"You picked the right time," Reisen Riou said. "That hydrology station you built on Ritou's still running strong, tracking water shifts."
Bona sighed, his smile bittersweet. "Back as Grand Sage, I was too busy. Now, retired, I realize you're the only old friend still kicking. Mondstadt, Fontaine, Liyue—most are gone or clinging to life like me. Their kids or grandkids run things now. Hit me hard, knowing I'm truly old. How do you long-lived types handle farewells?"
"You got me there," Reisen Riou chuckled. "I'm just an eighty-something youkai, not even a century. Older youkai taught me: stick to our kind. We live long, strong, and keep our circles tight. Doesn't dodge loss entirely, but it's rarer."
"Long-lived circles, huh? Enviable," Bona said. "Your wife's a youkai too?"
"Yep, and way stronger," Reisen Riou laughed.
"Smart. Scholars like us need a fighter spouse," Bona said, launching into a tale of his youth, marrying a Desert Oasis, a Gilded Brigade warrior. He shared lore: these women, dosed with special herbs, wielded water from the void, vital to desert brigades. Like Inazuma's samurai clans breeding low-tier deathsworn with Electro herbs, the drug inflicted hidden wounds, shortening lives. It pushed users past mortal limits (LV50+), but only effort drove further growth. For Inazuma, such methods were impure, clashing with martial purity—Reisen Anko had shunned them for that reason. The Brigade, chasing gold and thrills, embraced them, though the cost was grim: early glory, late decline. Bona's wife, younger by a decade, died from old wounds despite lighter dosing and top doctors.
Her tale sparked Reisen Riou's mind. If Inazuma could mass-produce Kairagi later, were there untapped Pyro herbs hidden in its soil?