I've yet to see a satisfying way to translate 淫紋 (inmon). I resisted the urge to leave it as is and went with lust crest since it seems to be the standard, but even that doesn't sit well with me.
I question the logic of this. 1.) her armor doesn't seem to provide any protection. 2.) if in this universe sex makes women stronger, two thoughts: a. Would she have won if she was not a virgin. so like did his whole plan revolve around a busty officer being a virgin? b. does this mean there are roving gangs of female yankee JK delinquents terrorizing the male population? c. is this the villians backstory?
The lust crest made them stronger, not sex. Sex is just how the villain breaks them. How a tattoo gives someone super human abilities is beyond me, though