I'll give the Shinobu arguments:
Doesnt Gaara’s sand armor scale way above the 8-B for Naruto 8-Bs. Lee can do some damage to it but it was still somewhat intact after the beat down from 4th Gate Lee so I don’t really see Shinobu getting past the armor to poison him. Plus speed equalised means that his auto sand would help block her hits as well. Once her sword hits the sand, he pins with superior lifting and squishes.
The Sand Armor is used as a last resort when Gaara decides to play defense; Lee was able to injure him before Gaara decided to activate it, and would've delivered more hits if he had longer reach. Sand Armor is also stated to have less defensive power than Sand Shield, so it seems more of a matter of Sand Armor regenerating and preventing direct hits.
Lee manage to peel lots of the Sand Armor at base, and piercing attacks with a rapier should have an easier time bypassing the peeling process.
Shinobu can push past her limit to a speed where she can comfortably blitz. She went from being crippled against someone who playfully attacks faster than she could see:
To moving too fast to track when she should be crippled from her injuries:
If Shinobu believes moving faster is the only way to win and survive, she can push herself to move much faster.
Base Lee had no issue pulling his limbs back, and Shinobu is accoustmed to using rapid stabs against demons with greater lifting strength.
Doesn't poison get rendered useless here because shinobu's poison only works on demons or does verse equalization cover that?
Wisteria in real life is poisonous if consumed by humans, so getting directly injected by it sounds really dangerous. Demons telepathically share poison mixtures used against them to adapt to them in advance, so Shinobu constantly creates new mixtures and switches them with her sheath; she has control which mixture is applied since she can purposely switch to a painless poison, so she properly can switch to a mixture that is extra-deadly to humans.
Also, without regeneration a good stab is all it takes regardless of poison.
Yeah but Lee is far more agile and was still getting tagged by Gaara, despite his speed amps and his acrobatics. She can't even hit him with her poison cause of his sand armor and sand auto blocking
Lee only got tagged after receiving the backlash from opening the Gates which momentarily incapitated him, otherwise he had no issue dodging Gaara's attacks. Doma's Freezing Clouds has better AoE than the sand, but Shinobu is able to evade it.
Also before anyone brings up Shinobu's aura, It's pretty garbage tier, The only instance I remember where shinobu had her aura showcased was against a fodder demon and even then that said demon didn't even get paralyzed or anything, She just got scared, Gaara being cold blooded should be unfazed by that
Doesn't mean it was used to its full extent; she only showcased it for a moment and then immediately stopped it, and for that moment it stopped the demon's breath and made her want to curl up in fear.
She should scale above this demon: