[Lee]

Originally Posted by Espy

Hrm...

There are a lot of teams, squadrons, and whatever known as the Red Devils, but "allied to [Japan]" makes me think... military group (?) of the Axis powers.

So that rules out the UK and the US, as well as France. The three main Axis powers were Germany, Japan, and Italy. But "responsible for the creation of" makes it sound less like a military group and more like... an invention? So, either a military group, or a military-grade invention, of either Germany or Italy.

You're almost there! Which one? Final guess. Double points for you if you can also tell me what Red Devils are.