Psi Reavers are an interesting enemy, as, rather than being truly flesh and blood, are in fact the psionic projections of a Psi Reaver Brain that you'll find nearby. The Greater Psi Reaver is unique in that it's the only one of its type, found when fighting the Brain of the Many. It has a huge number of Hit Points, about as many as a Military Bot, but does significantly more damage than a regular Psi Reaver. The same strategy remains: find its Brain and destroy it before moving on to the Greater Psi Reaver itself.

Attributes: Very high Hit Points, very high damage, medium attack speed, slow movement speed

Weaknesses: Anti-personnel ammo, incendiary damage

Common Loot: Greater Psi Reaver Organ

Strategy: As there's only one Greater Psi Reaver, you'd think it's not too much of a threat... well, you'd be wrong. The Brain of the Many is one of the most difficult fights in the game, due to the large number of Rumblers and other Psi Reavers floating around, and the Greater Psi Reaver is just the icing on the cake, as the damage it does is enough to kill most characters in a single hit, especially on Hard and Impossible difficulties. Your best bet for survival is to use any Agility-boosting items you have, or a SpeedBooster, and then running to the small floor indentations that surround the Brain of the Many and smashing the Psi Reaver Brains inside them. The Greater Psi Reaver's will be among them.