Luigi (SSBU)/Up smash
Luigi jumps slightly and swings his head from behind to front upwards. Nicknamed the 'Lead Headbutt' ingame, it is a powerful anti-air move for Luigi, possessing full head intangibility during the 5 frames the hitbox is active and has good knockback with a fair amount of range, capable of killing at ~125% with proper DI. It is fairly low in startup and endlag, making it a good out-of-shield option at frame 9, and the front hit is on frames 12-13, making it great coverage for landings or dealing with crossups on shield, although doesn't possess as much range as the back hit. Up smash's later frames are also capable of comboing into some of Luigi's aerials, such as forward, back or up aerials, which can lead to a fair amount of damage. The low angle that always sends towards Luigi can trip up opponent's DI with those unfamiliar with this property. Up smash possesses a sourspot on Luigi's chest, but is hard to land unless the opponent is almost touching him as the sweetspot has priority over it.
Despite the attack launching the opponent at an angle of 110°, it does not homogenize their falling speed.