|“||Men are beasts! Nothing More! We fight! We kill! We devour our prey! Beasts do not stand behind beasts, little prince... they use each other as long as it suits their own selfish purpose.||„|
Originally a thief born in the slums, Gangrel rose to be the ruler of Plegia, becoming known as the Mad King. He seems to enjoy war, and ignores Emmeryn's peace negotiations. Cruel and easily distracted, he enjoys deceiving others.
Gangrel spends much of the initial half of the game trying to start a war between Plegia and Ylisse as well as acquire the Fire Emblem, with little success due to Emmeryn's pacifistic nature and the importance of the Fire Emblem to Ylisse. Gangrel kidnaps Maribelle in order to further instigate a war and seize the Emblem, but the plan fails. After the attempted assassination of Emmeryn forces her to leave the capital, Gangrel attacks Ylisstol, causing Emmeryn to return to the capital to protect her people, allowing him to capture her upon her return. He plans to execute Emmeryn at the Plegia Castle Grounds. Chrom's army arrives right before her execution and stops it just in time. As they rush to Emmeryn's execution spot and sends in Phila to rescue her, Gangrels right hand Aversa summons Risen Archers and foils the rescue attempt. With the situation under his control, he gives Chrom the option to either relinquish the Fire Emblem or watch Emmeryn be killed by the Risen. However before Chrom makes his decision, Emmeryn sacrifices herself and falls off of the cliff to her death. With no one in power in Ylisse, Gangrel then prepares to attack the now Exalt-less Ylisse.
However, Gangrel's army begins to lose faith in him, refusing to fight for a pointless war after hearing Emmeryn's words. Gangrel does his best to snuff out any traitors with little success, leaving him with a weak force to attack Chrom's army at the Border Wastes and is ultimately defeated by Chrom.
It is later revealed that Gangrel has survived his last stand. Disgraced and broken, the only work the supposed dead king could get was with pirates, working as a servant and was, ironically, being treated like trash as he had treated his soldiers. Eventually Zanth's group encounters Chrom and his army and Zanth throws Gangrel onto the battle field where the two eventually meet once more. As a pathetic shell of his former self, he requests that Chrom end his life since he has nothing left and believes that Chrom must be dying to kill him. However Chrom, needing all the help he can get, convinces Gangrel to join his fight against Grima, rather than throw his life away.
After the war, Gangrel fell into obscurity. Some said that he found a new kingdom to rule and ruin while others said that he ended up in the gutters. Regardless, most people agreed that he was dead within a few years.
If the Avatar (the player) is female, it is possible for Gangrel to fall in love with her once he joins Chrom's army. Enough conversation between the female Avatar and Gangrel will eventually cause them to marry, and a promise from Gangrel to change his ways if he ever becomes the king of Plegia again. Gangrel also becomes the father of the Avatar's future son, Morgan.
These events change Gangrel's post-war story and his whereabouts become somewhat more vague. This alternative ending simply notes that the Avatar loved Gangrel more than anything. The existence of a future son also implies that Gangrel stayed with the Avatar after the war, but leaves the rest a mystery.