Sorry to double-post, but, well, I need to explain things further while at the same time bumping the thread. The problem is that, as described, S and SS-level NPCs are invincible, even to a group of A-level PCs. I know, I know, this might just be a mistake, but I don't like it when I assume is the main enemy is, well, unfightable, even with a cohesive group with complementing abilities.