I didn't think of Boa as an Empathic Manipulation user. Supposedly, she is, but from what I've seen of the anime, I recall her power mostly working on fodder marines who simply thought she was attractive. And in fact, most of her Amazoness subjects thought of her as the most attractive woman, too.
Who has it worked on, & what's the basis for Empathic Manipulation?
Has Saitama ever shown sexual or romantic interest in anyone, especially post-training? He seems dispassionate & his primary motivation is the thrill of a real fight.
I bring all this up because:
Weaknesses: She cannot swim and becomes immobilized if more than half of her body is covered in water, she is extremely arrogant, Her Devil Fruit's passive ability does not work on someone who isn't attracted to her (Example:
Luffy), or is feeling an emotion far superior at the time they would feel lust for her (Momonga was able to not be affected during the time she used her powers due to feeling the pain of him stabbing himself more than his lust for her)
And yes, her blows & projectiles could also induce it, but:
"However, sufficient concentration, being blind or blindfolded (and thus unable to experience Hancock's beauty), or simply lacking any sort of affection for Hancock can nullify these effects. On the other hand, she can also petrify her foes with her physical attacks as well as her techniques, regardless of whether or not the target feels lust for her, even working on inanimate objects or machines like Pacifistas.
But this use of her powers will only affect the area struck rather than the entirety of the target's body."
Also:
Tier: Unknow, At least
7-B, probably
7-A, possibly
higher
Boa is 7-A, maybe higher. Saitama is At Least High 6-A. It's true she could be higher, but to go from peak 7-A to baseline High 6-A, if I'm doing my math based on the Attack Potency chart right, you would have to multiply by: 4,969,552,501.2 times.
Meaning that Saitama's statistics are roughly a little higher than FIVE BILLION TIMES HIGHER.
If she only manages to partially petrify him, or just uses basic attacks or doesn't go for petrification from the getgo, even a VERY small portion of Saitama's AP would be sufficient to one shot her. If he can breathe with a slight amount of his AP, she'd probably die.
The risk for her of Boa not going for petrification first isn't helped by 1 of the weaknesses listed on her profile being that she's arrogant. Looking down on someone could make her just try attacking with haki or such.
So let's recap. For Boa to win, she has to:
1. Overcome her arrogance weakness & not assume this bald, non-amazon man in a dorky outfit is a threat, & use her petrification abilities ASAP, without arrogantly trying anything simple; Saitama is literally more than millions of times stronger than her & she probably doesn't know it.
2. Succed in Empathically Manipulating someone based on sexual/romantic attraction/lust who is quite dispassionate, & IIRC, has shown little to no sexual interest at all; Her petrification powers supposedly can NOT work on those who don't feel "affection" for her.
3. Ensure he isn't sufficiently concentrated otherwise (not hard) & experiencing of her beauty. Since being blindfolded can stop it, isn't it reasonable not looking at her could cause it to be avoided?
4. Not get hit by any of Saitama's attacks, including the massive AoE of his shockwaves if he punches hard enough. (Although, I'm not sure those may break her 7-A Durability.)
In any case, I'm not sure it's that easy for her, but, this is an open debate.