Fou-Lu is a character from the RPG Breath of Fire IV. He is part of a demi-god species called "Endless" and the other half of Ryu. Despite being a playable character for a few chapters, he becomes the main antagonist of the game, as well as the final boss.
After being summoned, the ritual was revealed to be incomplete and his soul splitted in two halfs. After founding the Fou Empire, he fell into a deep slumber, awaiting his other half, who would come six hundred years later.
After Ryu revealed himself, Fou-Lu awoke from his slumber and ordered Won-Qu to guard his tomb until he returns and walked into the forest.
He found two soldiers boasting about how his empire was unstoppable and even capable of slaying dragons. With a gigantic grin on his face, Fou-Lu proceeded to summon Astral Dagon and killed them.
While walking in the forest, General Yohm tried to ambush him, but despite having the advantage, he was easily defeated. He then proceeds to ignite the forest and cornered Fou-Lu to a bridge, revealing that the curret emperor would prefer to have him sleep for eternity and sends him falling to his doom.
However, Fou-Lu survived and after Bunyan's treatment, he heads to a mountain, but encounters Yohm again. This time, Yohm summoned a monster to take him out, but is easily defeated. Fou-Lu tried to escape, but he was extremely injured in the fight and crashes into the forest.
He awakens in a village under the care of a woman named Mami, who treated his wounds. She was the first human who showed him kindness and Fou-Lu fell in love with her. However, he heard about a "God" causing troubles outside the village and left to investigate. He found out that it was nothing more than a Rock Golem possesed by a spirit and destroyed him. After returning to the village, he found it under attack by his own empire. Thanks to Mami's help, he escaped the village and hides in the Soma forest. Mami was captured and taken to Yuna, who used her as the human sacrifice for his Carronade, a hex cannon capable of destroying enitre cities and countries, leaving a poison trail behind, which makes the land unbreathable. He fired the cannon with hopes of destroying Fou-Lu once and for all, but he remained unnafected. After discovering which person was used as the sacrifice, Fou-Lu laughed maniacally and decided to kill the one reposable for killing the sole person he loved.
He entered the city's castle, but is ambushed by Yohm again, who summoned two empowered versions of the same monster he had previously used before, but is once again defeated and reaches the conclusion that while humans are not as powerful as the "Endless", the vaule of their lives lie in the way they die and proceeds to commit suicide.
After arriving to the sanctum, he meets Yuna, who revealed himself as the one who used Mami as the sacrifice for his hex cannon and now, plans on stealing his powers. He calls upon the royal guard to subdue him and the diviners to cast a barrier, so they can capture him. However, the power of the dragon proved too much for them and were defeated. Yuna retreats, saying he will never forget this.
He enters the throne room and meets the XXXI Emperor, Fou Soniel, who attempted to kill him by using the Dragonslayer, a special weapon prepared specifically to destroy beings like him, but Fou-Lu remained unaffected and beheaded him.
He sat on the throne, announcing his return to power and waited for his other half.
There are two possible endings in the game: The normal ending is obtained by selecting "I don't know..." after Fou-Lu lists reasons that humans must not be allowed to exist, in which case the group fights Fou-Lu and finally defeat him. Fou-Lu realizes that humans were not bad as he tought they were and merges with Ryu, becoming the complete Yorae Dragon. With the remaining dragon gods deciding to leave life in mankind's hands, they remove their existance off the planet. Ryu loses his godhood and returns home as a normal human being.
The bad ending is obtained by selecting "Maybe so...", where Fou-Lu absorbs and kills Ryu, becoming Yorae Dragon. He then proceeds to kill Ryu's friends who tried to stop him and wipe out all human beings and, possibly, the planet as well.