Stage: stage 2
It is possible that Rainfire appears in Turbo Force as part of the Checkered craft boss; the game's data includes sprites for Rainfire near stage 2.
Stage: Normandy, France
Rainfire is the second boss of Normandy, appearing after the Me 323 Gigant. It seems to be a flying robot that initially attacks with fireballs and missiles. It moves very quickly, making it difficult to hit. Just before it is destroyed, Rainfire turns from silver to red and changes into a much larger craft with huge cannon arms.