A Battle... and then...
After a re-cap of what has happened in the war between the Transformers in this series, we see that Devil Z and God Ginrai are about to go into a battle which, as the narrator claims, could claim both of their lives. Devil Z laughs at Ginrai for coming to face him on his own, but then transforms and heads away as Ginrai grabs onto him.
He then tells him that he hasn't got time to mess around and since he's so sure that he's going to win anyway, he goes on to say that at the South Pole there is a machine called the "Devil thunder amplifier" which he will use to destroy all human life on the Earth. As Ginrai tries to stop him from moving, Devil Z calls out to Hydra, Buster and Overlord, saying that they have a last chance to prove their loyalty to him by destroying Ginrai.
Elsewhere, Minerva finishes treating Metalhawk's injuries, and he says that he will go and find out how the battle is going for Ginrai, but Grand tells him not to go and that he must be doing fine. They all decide to only go if Ginrai contacts them, but he might not get the chance to do that because Devil Z decides to give him a close range shot from his stinger blaster.
Ginrai isn't out yet though and keeps moving around quickly to get Devil Z to shoot himself a few times, whilst also ripping off his top side gun turrets. He then gets back on top of him and uses his jet engines to aim Devil Z back towards the ground and they both crash, although Devil Z manages to shake him off and then bury him under some ice.
Nearby, Hydra and Buster get up after taking a battering by Devil Z earlier on for their failures, but neither of the brothers seem to want to abandon their leader and instead and agree they that were punished fairly. And now, they must prove their strength by doing the only thing they can: fight the Autobots, despite that they are both in a weakened state.
The other Autobot Godmasters hear them talking though and jump down, but after seeing how beat up the two Decepticons are they at first say that they don't want to fight such weakened opponent. Hydra tells them to shut up and he and his brother start firing, but even though they are no match for the Autobots they refuse to give up. Meanwhile, the former Decepticons are on their way to lend a hand in the battle as Clouder has got a large attack buggy which has a ton of guns all over it.
Back at the main battle, Ginrai frees himself from the ice and then stomps Devil Z down into the ground he is on and plans to bury him, but the Decepticon leader gets out and transforms, and then uses his Devil power to use a ring projectile against the Autobot.
This attack is actually the technique he used to get rid of Hydra and Buster's human forms, and he plans to do the same thing to Ginrai but make him a lot weaker in the process. As this is happening, Grand picks up the large amount of magnetic waves Devil Z is creating and decides to go and check how Ginrai is doing with Shūta and Cab. Metalhawk wants to go with them but Grand refuses, saying that he will contact him when they know what is going on.
As this team of Autobots show up they see that Ginrai is in danger, so Grand tells him to duck and fires a shot from his ship's main cannon, stunning Devil Z and giving Ginrai the time to get in there and smash him about a bit, so much so that
something horrible happens to the Decepticon. As Shūta and Cab start to celebrate, Grand tells them not to do so just yet because...
...it seems that their enemy is not dead yet and as he gets back up, the word "transform!" is heard as Devil Z reveals that Black Zarak has a serpent monster mode!
Meanwhile Giga and Mega have decided that they can no longer follow Devil Z after what he did to them and the Hydra brothers, and will now fight against him instead. At the other minor battle, the good Godmasters seems to have won, but Hydra and Buster both get back up again and then transform and flee from the Autobots.
The new serpent mode reveals that each head has got twin blasters and as Ginrai does his best to avoid them, Overlord appears. Devil Z tells him to go and prove his loyalty to him by destroying God Ginrai, and as he floats there for a few seconds, Overlord then draws out his gun and takes a shot. But instead of going for Ginrai...
...and instead shoots at his former superior. Overlord then tells Ginrai that he is repaying his debt for saving him earlier on, but Devil Z calls him a fool and that says that he will show him what happens to traitors as he blasts the ring projectile at him.
This projectile does not turn Giga and Mega into robots though, instead, their bodies are disconnecting from Overlord and then thrown out to the ground in front of Ginrai. As Devil Z ends his attack on them, Overlord has not been destroyed and reappears before everyone.
And it is revealed that now, the Overlord Transtector has gained a life of it's own, just like how the same thing happened to some of the other Decepticons previously. Meanwhile, Devil Z resumes his attack on God Ginrai and blasts him across the ground and in the back a few times.
After taking a battering, Ginrai gets back up and something strange happens...the Headmaster Jrs suddenly feel incredibly hot and are all magically teleported onto God Ginrai, who then himself powers up and punches Devil Z back whilst checking on Giga and Mega, but Mega has already died whilst Giga passes away after saying that his only regret is that he never got to settle the score with him.
Overlord then charges at Ginrai, but thankfully Grand transforms to his larger robot mode and deals with him whilst telling Ginrai to head on and destroy Devil Z for good. Devil Z sends out his only remaining troops, but then Lightfoot, Road King and Ranger arrive saying that they will fight them and Lightfoot tells Ginrai to keep going.
As yet another fight begins, Ginrai heads back up to where Devil Z is and tells him that he will never forgive him for everything he has done, which now includes the death of his own comrades. He then tries his fire guts attack against him but he survives this and says that he was the one who bought life to the Godmasters in the first place and that he'll never defeat him. Ginrai then tells Devil Z that he has underestimated the power of humans...
...and then charges back at him with a more powerful version of the move he just tried, but this time it actually works and takes off Devil Z's heads and then the entire body of Black Zarak explodes, finally showing Devil Z to what he used to look like again. He asks Ginrai if he dares to anger him but gets no response as Ginrai powers up again and then charges towards him using yet another variation of the same move: the "final" fire guts. Devil Z tries to stop him but fails as he crashes straight into him.
What follows is a massive explosion, and as the flash of light dims down only one remains: God Ginrai! As the Decepticons see that Devil Z has been destroyed, Overlord gets the others to follow him into withdrawing and heading out into space as God Ginrai heads back down and lands in front of the other Autobots.
As he does this though, suddenly all of the humans are separated from their Transtectors and they all realise that their master-braces have vanished. They then see that their former Transtectors have actually come to life by themselves as they see that by destroying Devil Z, their purpose is over and they have separated from them. God Ginrai thanks the group for their help in defeating the Decepticons, but now it is time for them to chase after them as they have headed into space.
As the former Decepticons arrive, none of them seem to realise that they have missed the entire battle but it doesn't matter now as Grand is taking all of the Autobots into space as the others wave goodbye to them. The narrator then ends the series by saying that now Ginrai and the others have finally driven the Decepticons off Earth, their duty is complete and that Ginrai was always supported by the others - the other humans of the Earth.
Black Zarak's toy can actually be transformed into the serpent form shown in this episode, although it doesn't mention it in the instructions that came with the toy. This isn't the first time something like that has happened in a Japanese Transformers series though as Wingwolf, Sixshot's seventh mode shown in The Headmasters, was also something that wasn't mentioned in the toy's instructions but could actually be done to the toy itself.
As to where the former Decepticons got that buggy from... it was most likely a case of Clouder getting it as in the first episode he is seen in he seems to work at the US department of defence, so he may have had some links there.