Just to clear this up, Discord is the move that is putting the purple icon over a player's head. The 2 sets of 3 fireballs that come out follow that person. As Faytte said, Discord only signifies that the actual tank buster is coming right after. The tank buster itself actually is composed like 3 hits in real quick succession. Maybe one of them is called Empyrean Laser? I'm not sure about that (PS4), but I do know the flying text I always see when tanking that hit is Perpetual Ray. But it's completely possible each attack has a different name. I remember thinking how cool it was that ACT could pick up the 3 elemental dragons names in turn 9. It's like..."aww how cute SE gave these things we never target at all names" lol.
