Complex sentence: While the Soviets and Allies were fighting each other, Yoshiro was building up a massive high-tech military force bent on world domination, and demands that both the Allies and Soviets submit to Imperial dominance.
Split into simpler sentences: While the Soviets and Allies were fighting each other, Yoshiro was building up a massive high-tech military force bent on world domination. He will demand that both the Allies and Soviets submit to Imperial dominance.