I Reincarnated as a Farmer with S-Rank Soil, and Now I Have to Save the Dying Races with My Genetics Volume 6: Tides of Alliance

The ocean remembers when the world used to sing. For three thousand years, the Merfolk of the Abyssal Court have followed a single, desperate command: stay deep, stay hidden, and survive. But survival has become extinction in slow motion. As the coral bleaching spreads and warded nursery-grottos fail, Queen Marithys Tidecaller prepares to face the end of her people. That is, until a pure, untainted mana pulse echoes across the entire continental shelf—shattering three millennia of silence. The source of the pulse is Sanctuary, and the one responsible is Elian Blackwood. He is no longer just a reincarnated agronomist coaxing crops from gray soil; he is the pioneer of an expanding nation. When Queen Marithys brings a heavily armed war party upriver under the guise of diplomacy, she expects a cold transaction. Instead, she finds a thriving, multi-racial alliance of Elves, Dwarves, Goblins, and Kitsune, and a river that is aggressively alive. But as the ink dries on the new Verdant Accord, the fanatical Aethelgard Empire unleashes a heavy naval blockade at the river mouth, armed with devastating Null-Steel depth charges designed to hunt the Conduit races to extinction. To protect his allies and secure a vital new trade network with the Free Cities of Kethys, Elian must delegate a high-stakes subsurface counter-assault. But even as the blockade shatters, an unexpected miracle inside the Dwarven forge changes everything: the birth of a copper-haired son—the first male Conduit born since the Cataclysm. The extinction is no longer just reversing; it is breaking. And as ancient, long-dissolved Slime-folk awaken from the purified water table, the Dragonborn war-clans send an emissary with an ultimatum that will drag Elian from his fields and into a volcano-forged crucible.