Won't that be all males are fuck over in this world?
Some of them don't seem so bad (if this ain't a prequel but a different part of the globe and things aren't as bad as the first game or something) off. The tavernkeeper's got a pretty good gig going on before and after the town gets attacked, and the trader's probably making bank off of relics from providing potions. I just think a male holy warrior gets double-plus fucked in this setting.
It's not like we don't see female exorcists like Lilia and Rabiane get killed and/or eaten. Surely being a female means there's a chance the monsters would keep you alive as a milk/egg producer plus incubator, they still kill you if you try to resist. The plants and fungi surely don't care if you're female or male as long as you provide them with nutrients they need. If you consider being alive is the most priority, there's nothing stopping you from joining the evil cult as a male prist - you might even get lucky with a captured sister.
While I don't see how being a male prevents you from using magic powers like Lilia, it not like meele attacks aren't affective against those monsters. After all, Rabiane did fought with a sword, a bow & arrows. While not as powerful as Lilia's magic, they also don't rely on having MP to use.
If we're talking about game designs, it can be easily fitted for a male protagonist with some tweaks. Like having the monsters crave for human sperm so they can mix in human DNA to bring the alien god to the real world. While being a male means you can't produce your own egg, it doesn't mean you can't carry them in your warm belly and eventually give birth to them.
Maybe with the magic, sure, but consider just how actually fucked you are in story in this game. Like, let's say a guy shows up to do Lilia's job instead: same abilities, same stuff, only difference is they're a dude with all that entails. You can do the first bits of the game fine, but things start to get wonk as you head towards midgame: you legit can't get KO'd once by the demihumans or they'll murderize you, and the cult doesn't have much need for you, since you ain't equipped like Lilia to get knocked up with the Otherworlder, or whatever other kid game over's your ass as Lilia if you pop it out.
And that's a big ass problem, because you can't get through the northeastern village if they don't really want you. You fight your way through the villagers to the gate, but you can't get that gate open without the key and you can only get that after being KO'd one time, which leads to the parasite ending up in Lilia - they're basically trying to break your ass to knock you up with a kid, or something along those lines. They can't (or can they
ominous music intensifies) knock up male-Lilia, so if they get you down they'd probably go "hey this guy's the only real threat we have and they've got no value to our plans" and blast his ass into the next dimension. It ain't like they need to brainwash you - they've already got plenty of male cultists in the Cathedral. You're just a loose end they can tie up.
And even if you can get infected and they want to keep you around...my man, they're sticking a parasite worm
up your ass, and you're liable to get gangbanged by every man in the village to put more in you like in the Lilia knock down events. That's assuming you make it even that far in the game because if you get KO'd by the demihumans they'll just take your head off. Cathedral? They're not gonna brainwash you or try to give you a womb crest, they'll just dust you the moment they get a chance. With Lilia if you fuck up at least you have the fact that most people want to use your big curvy body for something, which can let her get back on her feet - escaping from the demihumans, or just using how the cult underestimated her at the northeast village to get the two sides of the key. That's not great, lotta rape involved, but better than a guy who'd just get RIP'd the moment they fuck up even once. The Otherworlder's whole shtick seems to be "have mutant babies" so as a dude you either die or get M-preg'd.
This is not the setting to want to be a male protag in, good grief. If I was a dude in this setting I'd rather be the damned trader, because half the time Lilia seems to come up to him naked and he can still pull trade goods out of his ass to replenish her supplies and make absolute bank in the process everytime she comes back to town. Like, we're not even trading him cash; dude's taking holy relics - I'd bet they're worth more than money, so whenever this blows over you fuck off somewhere else, sell the lot, and live like a king.
Like, maybe male crusaders don't actually have it that bad in general, I dunno about the broader setting and I don't think we know much about it or them, but they'd definitely not have a good time in this game's main storyline.