Berserker Lord

Its body is fused with the powerful phazon element, which conclusively makes it exceedingly more powerful than before. It has heavy armor which can not be penetrated by Samus Aran's weapons, but rather by the Beserker Lord's own projectiles which it shoots out at you. Once it starts to spew out the purple spheres, she'd have to shoot at them, which in turn would make it return back to the lord, which would over time start to destroy its armor.

Once its armor is destroyed, she'd be able to go up close and rapidly shoot at its week spot, which would soon enough defeat it. It became so badly damaged that it tripped into outer space, where it got mixed in with the ships that were dogfighting and eventually collided with an oncoming ship, thus killing both the monster and the pilot (as well as anyone else in the ship).