I think both yay and nay for this one. I think sword block being removed from infection game types is unfair. It's part of how you survive as a human. However, in normal slayer gameplay, I think it is fair. Because like the OP said, in slayer you've worked to get that sword and you've worked to close the gap between you and your enemy to get the close quarters slice. So basically, I think there SHOULD be blocks allowed in infection and invasion variants, just not in slayer variants.