Transmigrating to Ancient Times as a Spy

Not a Martial Arts World Where All the Settings Are Fused Together. I Want a Fictional Dynasty

Any recommendations similar to *I Really Run an Orphanage, Not an Assassins' Den*? The protagonist transmigrates into an ancient martial arts world, and the System rewards him with special skills. It must be an ancient martial arts world, not a modern setting, and no cultivation, either.