Heaven's Cataract is a Blue Bullet spell, learned from the Chac, Gucumatz, and Kukulcan enemies. It deals non-elemental magic damage to all enemies, and reduces their Defense and Magic Defense by two levels for the MP cost of 22.
Telluric Fury is one of Sephiroth's Bravery attacks, attacking with a four hit slashing combo with his sword while advancing forward. Pressing R1 with the right timing allows him to cancel the finishing animation into a dash.
Heaven is a common religious, cosmological, or transcendent place where heavenly beings such as gods, angels, jinn, saints, or venerated ancestors are said to originate, be enthroned, or to live. According to the beliefs of some religions, heavenly beings can descend to earth or incarnate, and earthly beings can ascend to Heaven in the afterlife, or in exceptional cases enter Heaven alive.
震天 "Shinten" is a Chinese verb that literary translates to "(something so forceful that it) shakes the heavens".