Gram

Gram is the protagonist of the Rengoku series. He is what others called "One of a Kind", as he is the only A.D.A.M that has a soul. He's also been called by "the Boss" or "The Captain" by other A.D.A.Ms under his command, as he is one of the strongest A.D.A.M in existence.

Appearence
Gram is a light blue A.D.A.M (although you can change his body color in the pause menu) and his appearance depended on the weapons he equiped and his skin became yellow. In all artwork he always takes the form of the weapons that's equip on him. Without weapons he looks like a human without hair, and has mechanical markings throughout his body.

Rengoku: The Tower of Purgatory
Gram, defeated by Gryphus and had been transported to the lowest floor of the Tower of Purgatory. He went to the 1st floor and faced Mars. After the fight, Grams wonders why A.D.A.Ms have to fight endlessly, and so he sets up a goal to fight through the floors again to discover why.

Rengoku II: The Stairway to H.E.A.V.E.N.
At some point, Gram's been transported to the lowest floor of the Tower of Purgatory, apparently suffers amnesia. As he defeated his former subordinate Mars in the first floor, he felt a strange electrical discharge from his body and saw a weird vision. Growing curious of the situation, Gram decided to fight his way to the top floor again.

As he progresses through the floors, Gram progressively regains his past memories, as he recalls Alcmaeon's name (whereas he still can't remember Mars, Minos, Briareus and Sphinx). The reason is because the Gram had been rediscovered by Beatrice, who is desperate to bring her lover back, and each time Gram defeated his former subordinates he regains part of his soul.

Once again Gram encounters Gryphus, same as before, they exchange talks about their past memories of the AI cell experiment and fight. Gram defeats Gryphus once more, but he told Gram that he cannot live forever and be sane.

Gram finally meets Beatrice, she is happy to see him again. But Gram is angry that she brought all the A.D.A.Ms back to life just for a selfish wish, and told her that the A.D.A.Ms are supposed to be destroyed forever after the AI cell experiment. Too angry about the situation, Gram attacks Beatrice, but she now was just a hologram. Beatrice told him that if he still wanted to fight, he could go to the Tower of H.E.A.V.E.N.

Gram went to the Tower of H.E.A.V.E.N and when he reached to the final floor, he met Deucalion once again. She congratulates him and told him to into the portal and fight up there again. Gram, realizing that it will be pointless to fight all over again, destroys Deucalion and went to the door behind her. On the top of the tower, Gram watches over the world. His fate remains unknown, as he disappeared from the tower after the credits.