So you've finished Bloodborne, clocked the secret ending, and now you're looking for a real challenge. How about playing it as top down dungeon crawler?
Not entirely sure why PaiNz V is going for the GTA connection when games like Diablo or Gauntlet seem like a closer comparison. Anyhooo, it looks like they're using a ladder in Old Yarnham to confuse the camera - climbing up and then running around in the scenery before falling back down, leaving the view lodged up in the rafters. This looks like a NG+ only affair if you want to give it a go, as the amount of health he loses when he hits the ground is pretty much the size of a low level character's entire bar. It's also not clear whether you need the co-op player in there as well to pull this off. If anyone has a try, let me know.