Board Thread:Warhammer 40k General Discussion/@comment-6134883-20130417202949/@comment-3258762-20130424175924

Let me remind you that a Sister can move slightly faster than a normal human thanks to her powered armor. A Space Marine can outrun a modern car at top speed, and that a Space Marine is said to "Move faster than is possible to react" Note: That means that a Sister cannot stop the attack unless they're lucky as they are simply humans in power armor. The Sisters are a respectable force, of course, but they are nothing compared to the Space Marines and especially not against the Custodes. The Sisters were one small part of the huge army that defended the palace while the Space Marines and Custodes were far outnumbered.

That is not to say a Sister of Battle is not a force to be reckoned with. They are utterly fearless, they have power armor, they have fire, they have zeal beyond almost anything else and, as a Roman General once said "There is little more unsettling in a battle than the warcry of a woman" and they could easily defeat any other human in the galaxy, baring perhaps an Eversor Assassin, but they cannot go toe-to-toe with Space Marines, not alone or with an equal force.