@fatalystic The word would not rebound, rebound only happens in unfinished conjurations. What should happen is that this specific word would be so powerful it would take almost hours to complete. It would end up being impractical to use in actual combat.
And If he tried to use it, he would most definitely be stopped and only then would a rebound happen.
There's also the fact that he is restraining himself on using certain words. He has already mentioned he is not interested in trying any words that could revive people, and he doesn't want to rely on instant kill.
@SunSun Yes, I also think this adaptation made the MC become far too generic. He was a much better character in the WN, almost unrelatable due to being an egocentric jerk, but very interesting to watch. THe side characters are also being underdeveloped due to some info being restrained in this version. At least the LN version should not have this last problem.
But so far, I'd recomend the WN version instead.