Isekai'd Before the Plot

A person is isekai'd into a familiar RPG world five years before its story begins, waking as Atreides Pennytree, the third son of a minor noble. Wanting a peaceful, luxurious life, Atreides hires a loyal swordsman to raid a cosmic cult and rescue five experimented children destined to become destroyers. He sends them to a well-funded orphanage, while his very limited mana keeps him far from heroic magic. The rescued children eventually form a worshipful organization around him, treating his offhand words as divine will.