GaoGaiGar - King of Braves, Vol. 4: Hammer of Heroes
The menace of the Four Machine Kings spreads, backing GGG into a corner.  Gai's ultimate attack, Hell and Heaven, is tearing GAOGAIGAR apart, and each time he uses it could be his last.  When a giant Zonder metal plant appears in the city, Gai doesn't hesitate to use the forbidden attack and sacrifice himself for everyone else. To save Gai, young Mamoru goes into battle himself.  With Volfogg, he attacks the Machine Kings in a last ditch effort to purify the Zondar plant.  However, the enemy cannot be driven back unless GGG fields its most unstable, untested super weapon: The Goldion Hammer!