Mr. Game & Watch (SSB4)/Up smash
Mr. Game & Watch performs a powerful headbutt while wearing a diving helmet. One very short hitbox, with a long period of invincibility on his head and middle-body hurtboxes right up until it comes out. Defensively, this is one of the best up smashes in the game. The biggest weakness of the move is the lag time before the hitbox comes out and some after it ends; but the invincibility helps circumvent this, making it a legitimate counter-based kill move. His legs are still vulnerable during the invincibility period, thus making some grounded moves capable of hitting. If approaching with an aerial, this move is a hard punish and can easily KO most characters at under 100%. When it whiffs altogether, it can be used again if they are too slow to punish the first one. Spamming it is viable when opponents are in KO percentages, but this is of course risky. If used on shield, it is completely safe at only -3 (along with high shield pushback). An opponent could be punished for dropping shield with a tilt, jab, or dash attack. Charging it at ledge as a get-up read or simply as a mixup can get even earlier KOs.