“Morphon Blighted Mind” is a command unit of the Taken.
A Taken Hydra. Unlike any other kind of Hydra they are not protected by the typical rotating shield.
Morphon has a very different defense mechanism. It will teleport a few times after it has taken some damage. There is no marker pointing to it so your team must hunt it down each time after it teleports. After the first teleport, expect to encounter more Taken Hobgoblins and at least two Taken Minotaurs.
The first teleport takes it quite a ways from its initial position. Head forward and over to the left. Morphon will start firing on you once you are in range or in sight.
The second teleport takes it nearby its starting position. It is at this point the battle changes some. It will summon small collections of data, manifesting much like an Oracle. Until these are destroyed, Morphon cannot be damaged. It will also call in a number of Taken Vex. You will encounter a number of Taken Goblins. Clear them out quickly and then turn your attention to the orb protecting Morphon. Morphon will be stunned for a time after you destroy the light. Use this time to quickly inflict as much damage as you can on it.
When you get Morphon to low health, it will start to Detain you. Do not leave the sphere because it will kill you. Unload on the sphere and break it to free yourself. Be quick about it because Taken Hobgoblins and other Taken Vex are on their way toward you.