"The only slight regret is that I can only instantly kill enemies with less than ten percent of their life value remaining. If the limit could be relaxed a bit, like to be able to instantly kill enemies with twenty percent or less remaining, it would be much more practical."
Zhang Yanhang estimated that abilities like this should continue to grow with the increase of Death Wave·Original LV.6's skill level. Perhaps it's unlikely to improve with a normal upgrade, but based on his experience, once Death Wave is enhanced to Original LV.MAX, there's a good chance it might improve.
After all, it definitely won't always be restricted to ten percent; ten percent is basically the brink of death. Unless it's a monster proficient in recovering life value, most monsters wouldn't likely survive after being reduced to this level.
