Better , but there's still a few spots that I spotted when reading through it:
Added in
Wrong tense
Delete
Like something out of an anime, it is a fully metallic robot crouched in a hand-to-hand combat stance. The metal creature's joints are too small to be used as armor, giving it away as being animated by the same nanites that were in everything these days.
Though the bottom half is covered in the stereotypical smooth metal mask, a visor right above had two glowing blue lights that must be its eyes. The outer parts of the helmet lack a lot of the ornamentation usually seen, though some paint on the right side just past the visor seems to be marking something.
Getting back up on his feet, the Shepherd launches into a series of attacks again, trying to overpower the robot and end the fight quickly.
Two sentences starting with "As" right after another - Some other wording would be good here:
" As the Shepherd is moved, almost gently, to be spread-eagled on the ground for easy access it seems obvious that the mecha has some means of penetration.
As the robot leans down to the back of the Shepherd, at this angle all you can see is the plates at it's crotch moving aside as a metallic penis slides into position."
A few more thrusts later and he buries his robotic manhood as deep as he can in his defeated lover, holding the furred body close as he obviously releases his metallic cum.