Also, the villains are dumbed down to what they were in Denzi.
Black Magma is exceptionally stupid even by tokusatsu standards to the point where I actively use them as a yard stick to measure dumb moments in toku. "Hey we have this doomsday weaponry that can cause sea-based transportation moot and have the entire Northern Hemisphere kneel before Zod-err I mean us! But lets attack just Japan and not actually conquer territory even though WE'RE STATIONED IN THE FUCKING ARCTIC AND ATTACKING JAPAN MAKES LITERALLY ZERO SENSE". Every other villainous organization has a reason to take over Japan:
-Being stationed here
-Looking for something useful in Japan (usually treasure)
-Vanity/pride/over confidence and the heroes being such a hated enemy that overtook common sense
-Actively attacking lots of targets at once and Japan happens to be the most difficult (see Giant Robo, Shaider, Ohranger, and Ultraman Gaia; I think Red Baron sort of qualifies since the Iron Mask Party came from space?)
Black Magma is ran by fucking machines, meaning emotions should serve no factor, and at no point were they looking for anything as their main goal. And since Black Sun is basically Sentai/Metal Heroes's equivalent to Quetzalcoatl why the Arctic? It's one of those things that adds more stupidity the more you compare it to something. But hey, the last six episodes sort of make up for it. I won't spoil it.
And this is the sentai they put into the Daicon Animations, ugh.