Earth is under attack from the alien invaders known as the Radam and is quickly losing the battle. With the planet’s finest defense, the space ring, being overrun without much opposition, mankind’s fate seems bleak. One of the few forces left to oppose the Radam are the Space Knights; but they are anything but successful. That is, until a mysterious man named Blade falls from the sky. Blade has the power to transform into a Tekkaman, one of the deadliest fighting forces in the universe – the very force that is leading the Radam onward! But unlike the other Tekkamen, Blade is obsessed with just one goal: defeating the Radam. Having lost his memory, he doesn't know why, but he knows he must stop them. With the help of the Space Knights he can begin uncovering his past, discovering who the Radam and the Tekkamen are, and of course, save Earth in the process!
In a world where Gods reincarnate themselves into the bodies of humans, Athena is the Guardian of Earth. Together with her 88 Saints, she must protect the Earth against other gods whose sole purpose is to take over her position and extend their realm; it has been so for thousands of years. In this age, Athena, along with her Bronze Saints Seiya, Shiryu, Ikki, Hyoga and Shun, will have to counter the evil plans of a traitor amongst her midst who rejects her identity and nominates himself as the sole lord of Athena’s Saints. Being the only ones behind the true Athena, Seiya and the others will have to battle their way through countless Saints to unmask this impostor.
Both series are about people whose great power comes from the armour they have. Theytry to protect things which are most important in their life even if it means putting their life into danger. One more simmilarity would be an kinda ancient style of graphic which the series authors used. If you liked one, you'd surely like the other.