yes, she is dangerous...which is also what makes her a very valuable ally. And yeah, MC's abilities (provoking arousal and very strong sexual attraction to him and making women more receptive to his suggestions + more submissive to him + addicted to MC) can't make a slave out of an enemy, but they allow to put a foot in the door of a neutral/friendly woman, and slowly gain ascendency over her. In this case, Layla is already better disposed toward us than neutral (helped her to seize power, she bear our child), and MC's abilities definitely give her hedonist self a reason to keep us alive rather than dispose of us (which, again, we haven't seen any reason for Layla to do so), and make me think on the long term MC will be able to at best grab the reins of the relationship, at worse be an esteemed equal in it.While true, she also has killed before so she could easily do it again and although MC can manipulate them a bit which I believe the explanation was he could exert a bit of influence not completely brainwash though.
And tbh, this kind of slow power play is one of the hottest aspect of the game. For exemple Luciana is a super smart woman, politically very powerful, under the influence of her mother and knee deep in an evil machination...and we're currently twisting her around MC's dick, phisically and emotionnally. She already weight positively her care for us against her obedience to her mother, and as MC continue to claim her and sink his hook deeper she'll end up fully under his whims. Personnally I'm hoping to make her discard this foolish cartoonish evil undead legion stuff, overthrow her mother and be the power behind the throne. Collared Queen in the streets, Submissive Bitch in the sheets