The Heart of Babel!? No kidding; the Heart of Babel? ...I don't what that is, actually, but it sure sounds powerful!
The Heart of Babel is a largely unseen character in Final Fantasy Brave Exvius and a member of Hess' Eight Sages. A technological innovation developed by Eclipsa, it was created to serve as a new power source for airships. How or why it was treated as a "sage" despite not being a living being, per se, is unknown. It was sealed inside the Wind Crystal during the Paladian Civil War and eventually grows massive enough to serve as the main engine for the airship Invincible.
Babel is an Aldore experiment developed by Eclipsa to create a source of energy to power airships. She could not make the Babel provide the necessary energy as it would shut down quickly, and thus took Heliarc's living heart, as he was rendered immortal and had great magical powers. Heliarc's living heart gave the Babel machine the energy source needed, but when he learned of what Eclipsa had done (being transplanted with his own Magitek Heart), he stormed Eclipsa's lab to confront her. Eclipsa revealed that his heart was inside a mechanical box, which served to house the Heart of Babel, but its contents could not be opened unless destroyed.
Heliarc defeated Eclipsa to reclaim his heart in the box, but could not open it. Pertira, his longtime friend, suggested they go to her hometown. They took the Babel with them, but due to both the Magitek Heart and the Heart of Babel being in Heliarc's possession, the Aldore government blamed the people of the Hess race for losing their valuable science projects, and discriminated and persecution against the Hess increased.
Yuraisha visited Heliarc and revealed the current state of affairs, seeking to create an organization that would protect Hess people like him. She wanted Heliarc to join her, as he risked being a target of the military should he remain in Pertira's town. He agreed, and Pertira joined them wanting to stay by Heliarc's side.
The Heart of Babel thus became owned by Hess and turned into the power source of the airship Invincible. Strangely, it was granted the title of "Sage of Hess". When the original Veritas of the Dark enacted a plan to seal the Sages in Crystal to force negotiations between the two factions, Babel was faced by an unknown member of the Sworn Eight of Paladia and sealed into the Wind Crystal.
When Veritas of the Heavens destroys the Wind Crystal 700 years later, he unseals the Heart of Babil to provide power to the Invincible as they needed a powerful airship for their quest for revenge. Dr. Lazarov steals the airship for his own purposes and attempts to use it as a weapon of genocide for his experiments. A fellow sage, Bahamut, was awakened after the Fire Crystal was destroyed. Sensing Babel's heart beating in the airship, the Dragon King challenges the vehicle and blasts the airship with his Megaflare. Lazarov is forced to hide for repairs and Bahamut departs.
Tower of Babel is from a story from the Book of Genesis in the Hebrew Scriptures/Old Testament/Torah, as well as other various ancient documents. The story tells of how early humanity was living in one city (violating the commandment to spread out and fill the Earth) and began construction on a great tower that would extend to the heavens so they could see God. However, God destroyed the tower and confused their language, forcing people to spread out among the Earth.The