Wearing an Intelligence-Reducing Halo, I Fight the Japanese

A transmigrator merely looks down on the present from the future of history. They’re still the same person they always were. But when a sneaky schemer gains an intelligence-lowering aura, everything changes.

The schemer’s rule is simple: if you’re better than me, I’ll lower your intelligence to the level my body had before. Then I’ll use years of experience getting by with low intelligence to beat you.