
That woman sounds like all talk.
Suwon for sure can see the worth and credibility of a person. I mean, he plotted his kingship and everything, he himself isn't a simple-minded, easily manipulated person.
And that woman thought she could have him twisted around her finger when they've only just met. Not to mention she was bold enough to proclaim that she possess the kinds of 'secrets' that can ruin Kai.
She's not that dangerous as she thinks she is. She looks and sounds like an impatient lunatic, eaten up and tortured by the Crimson sickness, so much so that she can't stay sane any longer.
I think it's because Itsuki was born and raised in the kind of environment that nurtures him into his best, have courage and explore his passion, as well as his strongest suits.
Meanwhile 2nd ML (what's his name again? It's past midnight over here ugh) was born and raised in a rather traditional Japanese family, hasn't got the time + chance + resources to find out his, err, 'ikigai.'
Plus, boys mature slower than girls, and I guess 2nd ML is quite close in age to Yuki.
Plus, Yuki is not any ordinary girl. In this sense I mean there're complications involved dating/marrying an audibly impaired person - it takes great deal of patience, perseverance, etc. and overcoming social/family's pressures.
Thus, his lack of confidence.