It should be known that the catastrophe sword was labeled as the strongest sword in the world before the Shadow Bringer came to light. Thus, even a piece of him that only had a portion of its strength left wasn't something to be trifled with.
In fact, if this piece of a sword was used by the elven youth, it would still manage to strike fear in the various apex clans saints if ever faced against it. Obviously, that's only if it could be used for a long period since the piece of the sword's hidden power is about to run out and cannot be recovered without the other pieces.
Meanwhile, for someone to dare and face this piece of sword with his bare hands, it's something no one would dare to do.
Unfortunately, the elven youth didn't know such a thing, and his arrogance was beyond the roof. Hence, he will have to blame himself for his own actions.
Boom!