An ISO volcanic research center is attacked. The God Phoenix, starting the investigation, is surprised by the Magma Giant and escapes into the sea where the Giant cannot follow it.
When Joe says that the Magma Giant's face resembles the face of Jesus Christ sculptured into a steep slope in the national park, the Science Ninja Team goes there to investigate. A girl climbing the Jesus Christ sculpture is suspected to be a Galactor agent by Joe and questioned, but she answers that she's here to sculpture the statue, continuing the tradition of her family in the third generation.
Together with the girl they go into the cave found in the steep slope and discover a base. The Jesus Christ face sculpted in the slope, is plunged into lava seething in the interior of the base and comes out as the Magma Giant. Seeing this, Ken calls the God Phoenix. At the top of the base, there's a special glas which is actually at the bottom of a sea. The sea is used as a lense to heat the magma, using the sunlight. With a rocket, they break the glas and thus destroy the base.
When a message comes in from Nambu that the Magma Giant is heading towards a city, the Science Ninja Team split up in their individual machines and lure the Magma Giant towards the sea. The Magma Giant cannot resist and steps into the sea. Through the sea water he's instantly cooled and becomes a black piece of rock, standing still.
The girl then gets her chisel to begin sculpting again.