Ah, okay. Yeah, both are not easy to control, but if you want movement options and rapid assaults of attacks, both Sheik and ZSS are good at that.
You're right about Sheik
, she has a tough time getting the KO - more than ever now that they nerfed her Back air with the new patch. She now needs to secure the KO offstage for sure, though she can somewhat mitigate herself going offstage since she has Needles and Burst Grenades to control space offstage. She goes about getting the KO with Bouncing Fish (Down-B), U-smash (the tip of her hands are very powerful), or offstage with Back air (which got nerfed). The first hit of her Vanish UpB is also very strong, though this takes a read. Up-air can KO at high percents off the top blast zone, but that's if you're at high percent yourself (this game has rage, present in Tekken, which increases Knock back in moves if you're at high damage).
Zero Suit
can KO offstage or onstage, her options are varied and she can carry the opponent either sideways or up towards the top blast zone, or simply end them right then and there. Flip Jump can hit opponents automatically once you are on top of them, she'll bury them in the ground making it easier to connect the UpB. This works offstage for spiking the opponent downwards too. Her Paralyzer neutral-B and Down-smash help trap her opponent and set up these opportunities for her. Her other KO moves are Back air and Forward smash.
Both Sheik and Zero Suit are top tier characters, a majority of the smashers here will agree with me on that. They are tough to use, but their reward is well worth it. This also means that Zero Suit and Sheik are well represented by a lot of players, so if that's not what you're looking for, then read on.
If you're looking for a more unrepresented character that can still win you games,
is on your list. He's by no means a bad character, but did receive significant end lag to his moveset in this game which made some former players quit him or keep him as a secondary instead. Lucario's gets Aura, which is a magnified version of the Rage mechanic: the more at a disadvantage he is, the more damage and knockback his moves deal. Also applies with stock disadvantages. He attacks with Aura, the blue fire in his moves, which gets bigger the more damage he has (meaning his range also increases with more damage). He does require commitment though: his attacks have significant startup and notable ending lag, but are otherwise powerful and disjointed with the flame at the end of his moves.
If you would prefer someone who has better movement but is still under-represented, I suggest looking at
. His neutral game is a tad slow, but he has good mobility and very high jumps that let him chase opponents in a lot of directions.
I suggest checking out the character boards for these two.
isn't represented too much but everyone agrees he is solid.
His multiple jumps means he can safely take to the skies if you feel overwhelmed onstage, and also makes recovering pretty much guaranteed especially with an Up-B that covers a lot of distance. So if you're not comfortable with being offstage yet, his multiple jumps and long recovery should leave you at ease. He gets disjointed range with his dual swords, which is always a good thing to have so he can keep safe distance from his opponent in the melee.
By extension, if you get comfortable with Pit, you shouldn't have much trouble switching between him and
. Their differences are in knockback, their arrow projectiles, and their SideB arm attacks.
basically is an easier Marth, she doesn't require to align the tip of her sword to get the most out of her.
in the end is harder to use but better than her though.
Marth wasn't changed much in terms of moveset, but numerically he was gutted: he can not auto cancel his moves freely like he used to before, his neutral game (ie, "A" moves or standard moves) has notable lag now in a lot of his moves, his jab deals little knockback to make it worth using, and his throw game is among the worst now.
They do have good movement, however, among the fastest dashing and walking speeds in the game, and their range is still disjointed. They just don't allow for a lot of error, since the ending lag in their moves leaves them very exposed.
tl:dr,
are top tiers with great movement, but tough to use and represented a lot.
are mid tiers who aren't represented too much, but still have solid movement while having good KO power.
are not represented a whole lot either and have multiple jumps to leave you at ease if you find yourself offstage.
got gutted in this game with lag to their moves, though their mobility itself is still good.
IMO, if you want unrepresented characters with good mobility options that will still let you win, I suggest Lucario, Greninja, or the Pits.