Responses
All excellent questions that I've wondered myself (and what kept me reading), but at this point due to the update pace and the next 1-+ future chapters all being mob rape (which took the author seven real life months to draw), I'm losing hope we'll ever get satisfying answer to this story. If you're interested tho, I have a fanfic that goes into the lore

Is the plot with us? Or did it get lost? I have a lot of questions.
whats the Leon's origin? Is Leon transmigrated from Earth or is it another fantasy world? The story kinda hints that Leon have some sort of connection to royalty in his original world
Who's this Cliff guy beyond Leon's guardian and 'lover'? (Cliff hooking up with a kid he practically raised really gives off predatory and grooming)
The part where Cliff got attacked by someone, is that guy Negral?
If that world is perfectly suited for that monsters, then why are the Negral and his cohorts are obsessed with making that world 'livable'? Like wasnt that world already livable?
Are they tourturing Leon out of revenge or for the need? I know for sure that Deus guy is delibrately torturing Leon as a revenge for attacking him and that creepy doctor/scientist guy also does it because Leon's attack caused a parasite to take over half his body
Whats with Negral's obsession with Leon? Why does he dont want Leon to go away? But then is willing to let others have their way with Leon?
Why do they need to repopulate? Dont the population there can reproduce? Why do they need specialized 'vessel' for repopulation?
Why is repopulation heavily dependant on Leon? Just why??
So this plan for repopulation where they are going to breed monsters with Leon, lets assume that for a moment, after this then what? How are they going to create future generations beyond? Do they find someone like Leon? Do they summon creature?
Did they steal the Leon's power once they figured out he's a perfect host? How long were they planning?
So Negral, Deus and others human appearence are all just false? That means like beryl they have true appearence?
Negral is very much focused on controlling Leon and he knows Leon is immune to mind control but is weak to physical touch. Why does he wanr to control Leon? (I suspect after ch 81, Negral threw Leon in purgatory to break his spirit and willpower and make him succumb to physical touch by the monsters so that Leon can be easily to manipulate)
What's the origin of Leon's power? Is it Cliff's? Is the power passed on to Leon as innate or is the source the earrings? If the power source is indeed earrings then why when Leon gets back his earrings unable to fully unleash his power? Did they seal the power itself or did they block the Leon's ability to access the power?
Whats the endgame for Leon before he gets tortured? And whats the endgame for Negral and co? Whats driving them? Whats their goal?
The story has a lot of plot to explain but the majority of content is all about Leon getting tortured to the point its starting to cause discomfort like for what reason is he being put through such pain?
Its not purely billed as fetish porn atleast in that way it can simply be written off as something people use it for their voyeuristic pleasure. It hints at background and story and expects readers to push through a lot of graphic content without any meaningful story to grasp