The Tower of Rem is a tower located on the Quibi Peninsula in Tales of the Abyss. The tower formally resided in the Qliphoth, and served a last resort, designed as an attempt to travel to another planet in case the Float Project failed.
During the Dawn Age, the Tower of Rem was built at the center of a mining city in case the Float Project failed and the miasma consumed all of Auldrant. However, construction halted when the Sephiroth Trees successfully raised the crust in the sky. As a result, the Tower of Rem was left incomplete, as well as left in the Qliphoth, along with the entire Quibi Peninsula.
Tales of the Abyss
During the events of Tales of the Abyss, the safe descent of the Outer Lands rejoins the Quibi Peninsula and Tower of Rem to the rest of Auldrant. When the miasma resurfaces, Jade Curtiss states the only way to neutralize the miasma is through the sacrifice of ten-thousand Seventh Fonists, or at least potential Seventh Fonists. However, Asch manages to find a substitute: ten-thousand replicas and himself using the Key of Lorelei as a catalyst for the reaction. Luke fon Fabre and his companions attempt to subdue Asch when they are attacked by Dist and his "Kaiser Dist XX". The party defeats Dist and reasons with Asch and the replicas about the situation. In Daath, Luke volunteers to take Asch's place due to his self-loathing feelings about being a replica himself. At the gate, he uses the Key of Lorelei and the power of his hyperresonance to absorb the Seventh Fonons of the replicas, along with the miasma. The plan succeeds, and Luke survives by bizarre means. At Belkend, he learns that his fonons are undergoing rapid separation, giving him only a few months to live. Knowing that it will cause unsettlement amongst the party, he decides to keep it a secret, with Jade being the only other person to know.