Riverelve
"As much as he was skeptical concerning new half-siblings and feeling averse of the thought of having children himself, biologically or ... the proposed way, he felt incredibly disgusted. These were very young kids, kids who couldn't have caused any harm that would somewhat justify wanting to murder them, kids who should be able to enjoy a safe, happy childhood and not have to worry about getting killed over being their father's kids.
If lying to them and taking over this responsibility really was the only way to protect them, then perhaps it was worth it. Half-siblings or not, any living children deserved better than this.
Zagreus slowly nodded. "I ... see. In that case, I, er, might do that. For them.""
Or, a PJO-Hades-Crossover/AU where, for the sake of his newest demigod children's safety, Hades asks his immortal son who never had kids and whom no one on the surface ever heard of to claim this children instead of him and nobody really knows how to handle the situation.