As far as I'm aware, he does only empower women, so the 'Prince of Zahard' title either means an actual biological child, or something else entirely (of course it could also be that he's like Anak, and is the son of one of the Princesses, though I think his importance is probably higher than that). Honestly, only giving his power to females makes sense when you take into account he's also trying to control how much of his power is spread around, since a dude could potentially knock up a couple dozen women before his actions are found out, and then tracking them all down can be difficult, while a woman can only have one child at a time and it becomes pretty obvious once she starts showing.