Will I, Dark Blue, Come and Fight Amber King?

In one operation, Deep Blue left his hope of life to his teammates. He cut off his own chance to survive, leaving his hope of living to others and leaving death to himself. He vowed to protect his comrades to the death, even if he sacrificed himself. I will protect you at all costs. The mysterious giant gives power but everything has a secret price. It is not currency but something deeper, a strange world, a train.