Here's another strategy.
I find it easier to use a bow to hit one of them and then use a Purple Flame Shield +10 and wait at the top of the stairs. They charge at you with their spear, but it rebounds off of the shield. I equip the LSoM in my right hand and swing at the Red Eye Knight until it is dead. Thief's ring is kind of useless because you have to be closer than without it to the Red Eye for it to charge at you, It may occasionally charge in your direction and walk back, therefore you wasted an arrow.
In this case, I guess Blind would work just as well.
