Luigi (SSB4)/Dash attack
Luigi's dash attack is a series of cowardly punches. It's a very fast move (frame 4), making it decent as a burst option to punish whiffs. Thanks to its horizontal knockback, it's good to set up edge-guardings. The linking hits are very hard to escape, meaning the move is unlikely to drop an opponent before the last hit.
However, the move is plagued with very high endlag (IASA 76). Because of this, it's extremely punishable on whiff and on shield. In result, it's rarely used in competitive play.