Luigi's kick, known as Plumber's Boot, at first glance looks like a stereotypical Sex kick. The hitbox comes out on frame 3, the move lasts longer and gets weaker the longer it's out, it's a Nair, and it has a fast landing lag of 7 frames when successfully L-cancelled. One big difference, though, is the angle this move sends opponents: specifically, 90 degrees straight up on both the early and late hits. This, combined with Luigi's difficulty in approaching from the air, changes the role of the move from that of most Nairs/Sex kicks (being approaching moves/neutral openers), to that of several roles: A combo starter, a combo extender, and a combo breaker.
The move's fast startup and large priority means that, when you're being combo'ed and out of hitstun, throwing the move out has a decent chance to beat the opponent's next combo move, and even lead to a reversal, as it's such a good combo starter. However, you do this at your own peril, as just spamming it typically leads to it being baited out by opponents and then massively punished. In addition, because the move launches players upward, it can be used to juggle opponents, especially fast-fallers, with the strong hit being used at early percents and the weak hit at mid-to-late percents, though you'll typically want to mix in other launchers such as Luigi's up-tilt or down-smash to unstale it.
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Kick
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Kick
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