This story is a sequel to Equestria Ninja Girls: Shell Shock
The Ninja Turtles and Rainbooms help the half-Atlantean, Aquaman, to find the lost, ancient artifact of Atlantis that could help him dethrone his half-brother, King Orm, who leads the underwater kingdom of Atlantis and seeks to unite the seven underwater kingdoms against the surface world that will lead to war and bloodshed.
This story is edited, proofreaded, and approved by Wildcard25 and Red Tagg.
Disclaimer: Neither Darth Wrex, or I own Equestria Girls, Teenage Mutant Ninja Turtles (2012) or Aquaman.