Mazinger Z vs. Devilman

Mazinger Z vs. Devilman is a 1973 animated feature that unites two then-popular anime series, both created by manga artist Go Nagai. During a clash with some foes, Mazinger Z inadvertently hurls them into a volcano, where they crash into the prison of the Satan race and release Phoenix Jenny! Dr. Hell, learning of the incident, frees the rest of the Satan race and forges an alliance with them to defeat Mazinger Z, their flight abilities proving too formidable for our hero. Meanwhile, Devilman also battles the Satan race members individually, but their combined power proves overwhelming as well; can Mazinger and Devilman put aside their differences and team up to defeat Dr. Hell and the Satan race?