User blog comment:Dtuck010/Who killed Tula and drove aqualad to black manta?/@comment-187.173.223.33-20120513191134

I believe it has something to do with Ocean Master being removed from the light. I would not be surprised if Black Manta somehow forced or tricked Ocean Master (who probably had a hand in the death of Tula) to disgrace himself thus inadvertedly allowing Black Manta achieving pearsuation of his son to join him, as well as achieving a higher position within the light (2 birds with 1 stone).