Talpa, ruler of the nether realm, has come to rule the mortal realm. The Ronin Warriors, assisted by their pet tiger White Blaze, a child (with a skateboard...) and a girl, try and stop him.
They fight the Dark Warlords, Nether Spirits, Talpa's soldiers, and many more bad guys on their quest to save the Earth.
The five Ronins are powered by magical armors, but they were made from the same place as the Warlord's armors.
Talpa tries to stop the Ronin Warriors countless times, but in the end is defeated by a six year old (aided with a mystical jewel, of course)!
The five Ronin armors can join powers to make the Armor of Inferno, an armor that could easily destroy the mortal realm. It is one of the key things used to stop Talpa.
There are also these guys called "ancients" who are spirit guides to the Ronin's. When the Ancient dies, Anubis, the Dark Warlord of Cruelty, becomes the new ancient. He ends up sacrificing himself to free Lady Kaira from Talpa's evil grasp. She, being the last of the Ancient's clan, becomes the new Ancient.
To learn more... read the manga's or watch the show. Cartoon Network took it off the air, so good luck!