Giga Bowser Punch
From the Super Mario Wiki, the Mario encyclopedia
Giga Bowser Rush is Bowser's Final Smash in Super Smash Bros. Ultimate, replacing Giga Bowser from previous games. Upon activation, Bowser transforms into Giga Bowser, appearing in the stage's background at enormous size. Giga Bowser makes a fist and aims a player-controlled crosshair towards the opponent, similar to that of a Dragoon. The punch deals 40% and launches opponents; if the opponent(s) are at 60% (or 80% if using the FS Meter version), Giga Bowser's punch will instantly KO the opponent(s) instead.
There exists a coding bug which causes Giga Bowser Punch to send opponent towards the upper blast line, when they are normally supposed to be screen KO'd; specifically, opponents pass through any hazards or platforms until they go beyond the blast line. Such stages include: Mushroom Kingdom, Mushroom Kingdom II, WarioWare Inc., 75m, Mario Bros., Hanenbow, Dream Land GB, Mute City SNES, Balloon Fight, PictoChat 2, Flat Zone X, Wii Fit Studio, Pac-Land, Super Mario Maker, and Umbra Clock Tower.