Tower of Heaven

The Tower of Heaven (楽園の塔, Rakuen no Tō, literally the Tower of Paradise) also known as the R-System is a taboo Magic structure that can be used to restore life to a deceased person.

Location
The Tower of Heaven was formerly located on a small island on the coast of the Ka Elm Kingdom south of Fiore.

Description
The Tower of Heaven, or "Resurrection-System" is a Magic Item that allows any person to restore life to someone who is deceased at the cost of someone else's life. In the interest of protecting the order of the Magical world, the construction of the tower had been forbidden by the Magic Council since ancient times. However, a cult wishing to revive Zeref began work on it years ago. The cult kidnapped children and adults alike and forced them into slavery so that they could construct the tower. Through the efforts of Erza Scarlet, the cult was defeated. However, a possessed Jellal Fernandes, continued the construction after bribing Erza and forcing her to leave the tower. By the year X784, he had completed the tower and was ready to use the tower. In order to, he needed a sacrifice with a tremendous amount of Magic Power and so he chose to use Erza Scarlet as a sacrifice to revive Zeref.

History
The towers were a series of structures that Dark Mages tried to construct and use in order to revive the most powerful Dark Mage in history, Zeref. A cult that worshiped the Black Arts invested a large sum of money to initiate the building of the R-System. There were seven towers originally, but the Magic Council put an end to their construction, though they never found the 8th tower off the coast of the Ka Elm Kingdom. The cult kidnapped many slaves in hope of using them to complete the tower, using inhumane methods of discipline to keep the slaves in line.

However, the reign of the cult came to an end because of a slave revolt in the year X776. It all started when a slave named Erza Scarlet was punished for leading an escape attempt by being tortured and losing her right eye in the process. Another slave and a friend of hers, Jellal Fernandes, came to her rescue and saved her, but he was captured by the prison guards. Distraught at his capture, Erza led a revolt to save him which was successful, but Jellal had been brainwashed by Ultear Milkovich, who he thought to be Zeref. So he bribed Erza and forced her to leave the tower and kept all the other slaves at the tower albeit with much better conditions and decided to finish the tower and use it to revive Zeref.

Magic & Abilities
Resurrection System: True to it's nickname, the R-System or "Resurrection-System" allows any person to restore life to someone who is deceased. However, using this ability does not come easily. To complete the process, an enormous amount of Magic Power is required; 2.7 Billion Edeas. No Mage can possibly produce that amount of Magic Power, as a matter of fact, the only thing that can produce that kind of energy is Etherion, a weapon owned by the Magic Council. Erza Scarlet stated that not even the combined Magic Power of all the Mages in the continent would be enough to produce such a substantial amount of Magic Power. After receiving the energy it needs to be activated the tower transforms into its complete form. A giant Lacrima crystal that is blue in color. However, even in it's complete form, it is not ready to use until it receives it's second activation requirement: a sacrifice. The person who is sacrificed must have Magic Power that is on the same, or at least very close to, the level of Magic Power of a Ten Wizard Saint. The body of the person sacrificed is then fused with the Lacrima that is used in constructing then tower. After fusing with the Lacrima, the body is then broken down and reconstructed into the body of the person that the R-System is meant to revive.

Notable Events
During the year X784, Jellal Fernandes had his subordinates, who, along with him, happened to be Erza's childhood friends, kidnap Erza Scarlet and bring her to this tower to be used as a sacrifice to revive the most powerful Dark Mage in history, Zeref. However, Erza broke out of the cell they were keeping her in and met up with her guildmates (Natsu Dragneel, Lucy Heartfilia, Gray Fullbuster, and Happy) as well as Juvia Lockser. Natsu and co. had come to the tower to rescue Erza. Upon meeting each other in the tower, they all went throughout the tower determined to fight and defeat Jellal and his forces and stop his plan. In addition to his subordinates: Simon, Shô, Millianna, and Wally Buchanan, Jellal had also hired Trinity Raven, a group consisting of three powerful assassins from Death's Head Caucus to assist him in his plot.

Natsu and Gray fought Fukuro, a member of Trinity Raven who looked like a humanoid owl and who used Jet Magic and Absorption Magic. Natsu was defeated, consumed, and almost digested by him, but Gray stepped in and saved him. Lucy and Juvia fought Vidaldus Taka another member of Trinity Raven who used Guitar Magic. Through the use of Unison Raid the two Mages defeated him. Erza fought and defeated the leader of Trinity Raven, Ikaruga. She was a female Mage who specialized in Sword Magic and was powerful enough to destroy some of Erza's most powerful armors. Ikaruga revealed that the Magic Council was planning to use Etherion to destroy the Tower of Heaven. After defeating Ikaruga, Erza went on to face Jellal.

Destruction
Jellal and Erza fought and eventually Erza began overpowering him. Once she defeated him, instead of killing him, she pinned him down and said that she planned to die there with him once Etherion was fired at the tower. Jellal convinced Erza that he had given up on his plot and that he wished to die with her as well. The two Mages hugged as the council fired Etherion at the tower. After the blast was over Erza was surprised to see that she and he were still alive. At that moment Jellal used a spell called Bind Snake to bind Erza and he explained that it was his plan to have Etherion fired at the tower because he needed a lot of power to activate it. Jellal then pushed Erza into the tower's Lacrima walls in an attempt to sacrifice her. However, Natsu Dragneel arrived and saved her. After defeating Jellal, Natsu collapsed from exhaustion and Erza was determined to get out of the tower so she attempted to fuse herself with it to stabilize it. However, the tower still exploded, and thus, it was destroyed. Erza, however, was not killed in the explosion because Natsu had somehow managed to save her and him from death.

Fights

 * Natsu Dragneel, Lucy Heartfilia, Gray Fullbuster & Juvia Lockser vs. Tower of Heaven Guards
 * Natsu Dragneel & Happy vs. Wally Buchanan & Millianna
 * Natsu Dragneel & Simon vs. Fukuro
 * Lucy Heartfilia & Juvia Lockser vs. Vidaldus Taka
 * Gray Fullbuster vs. Fukuro
 * Erza Scarlet & Shô vs. Ikaruga
 * Erza Scarlet vs. Jellal Fernandes
 * Natsu Dragneel vs. Jellal Fernandes

Trivia

 * Although the kanji (楽園の塔) for Tower of Heaven translate into Tower of Paradise, the official English distributers of Fairy Tail called it the "Tower of Heaven."
 * The exterior and interior design for the tower are completely changed in the anime.