This might seem trollish, but it was Leshma when I started. He could block everything and kill multiple guys at a time. Since then I think he doesn't take it as seriously or got bored playing to win
Actually, at that time I had 71 body armor and hits were bouncing off me (most people had regular gear). I couldn't block everything but I could turn around, drag overheads, at some point I was able to hit through enemies before cmpx patched that.
I was high level, with epic gear while most people weren't. That's all. Also cmp did everything in his power to minimize impact single player has on battlefield. Especially against groups of enemies. You know how it's hard these days to kill group of anything, especially shielders (that used to be walk in the park).