@BHswordsman09 is right. Lower tier opponents may not catch on quickly enough, but upper tier opponents know how to deal with it easily. Your -3 on the “superhero landing” explosion, which leaves you very open on whiff. On block you have to either cancel into a shadow move, usually inferno, follow up with fireflash, throw attempt, or backdash. There are a few options on block to go with, but without shadow one of them is eliminated, and any of the other three are basically guesses, 2 of which are mildly more safe than the other. Most characters will have ways to combat some of these other options though.
I’ve used it enough to know eventually you can be punished for overusing it.