Samus is good at killing. That's not one of her major flaws.
Her nair is one of the strongest of the fast front facing aerials (I think second? Actually third counting Zelda's sweetspot fair) and has a horizontal knockback angle. That combined with its lingering hitbox and her floatiness makes it really good at edge guarding. If Samus is in a good position and gets a read on the opponent's SH with nair, then she can get a kill (early with rage) or if they're at 70+, put them off stage.
CS is the best chargeable projectile for killing not just because of its speed compared to the others (and power compared to ones other than Mewtwo's and aura Lucario's), but because of how she can put opponents in situations where they get hit. She has tech chases that lead to CS at all percents, but the relevant ones as far as killing are jab combo to CS, sourspot ftilt to CS (inescapable as far as Samuses know), zair tech chase to CS, and if they survive to high percents, then jab 1 tech chase to CS.
Bair obviously kills really early and that and nair give her two solid killing aerials also usable out of shad.
Those are three reasonable moves that kill pretty early, like ~100-130 range. Her edge guarding is fantastic as well. Other early kill options are uair combos to up b on platform stages or kill combos off of missed techs on utilt/dair. And actually her usmash kills around 120 as well.
At the 150ish range, up b OOS, uair, fair, tipper ftilt, unteched utilt, and dash attack start killing, which is most of her moveset. Falling uair to jab to fsmash is a pretty good kill combo
Her advantage state is amazing with her juggling, combos, edge and ledge guarding, tech chases, and powerful moves.
Her disadvantage state is meh. She can't land on stage reliably and has to go the ledge a lot when she gets juggled. What keeps it from being terrible is her weight, ability to escape combos, recovery, and ledge options.
Her neutral game is kind of limited. Her midrange game is amazing, and her neutral can be somewhat threatening with dash attack, zair comboing into dash attack, nair, and obviously CS. But she can't stop strong approach options and she can get forced to the ledge really easily. Her grab sucks and keeps her from playing a dash attack/grab based neutral that would otherwise be quite good with her dash attack. Camping or idling against Samus will cause you to lose if Samus gets you in her midrange. It's always just better to be aggressive against Samus and a lot of her bad mus like MK, Pikachu, Sheik and Fox are very capable of that. And characters like Ness, Ryu, Luigi, and all of the heavier characters struggle.
I think she's a pretty good character that's in a game with better characters that keep her down. As opposed to low tiers in other Smash games that are actually bad and not redeemable.
Also, the only good active Samus players right now are YB from Japan and Afrosmash from England. Nobody plays this character.
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