@Ulthair while that's weird but considered as effective tactics. You see, in every full battle story the best time for counter is when the enemy think they already win, in this case dead is one of possible condition. Another reason for author creating weird weapon like that for protection matter i guess, but still that's not usually like that
@Ulthair : In Matthias's time as Gaius, only someone who could control their mana would be trusted with such a sword. People who could not control it were likely the rarity. Plus, a weapon that saves you from death is very valuable.
Well, at least they stopped the stupid "Hahaa, but I'm not the real uber-mega-hyper strong mastermind, but the guy behind me is and he's coming for you hahaha" -routine. Not that this is much better...