uh.. the dragon. you forgot about the dragon.
you see, MC is a DRAGON having intercourse with all those human females.
that's pretty much bestiality at the core of this game. they can't Off this tag.
Debatable. Core kink of bestiality is relatively brainless partner. Its to debase oneself by laying with your absolute lower... of a lover. Sorry, couldn't hold myself.
But our bad dragon is sentient being. He is not an animal despite looking beastly - oh, and he is not an actual animal in most literal sense. I am quite certain many people distinguish actual beasts from real life, whom they can easily associate with bestiality, and mythical or fantastical creatures - those will take some modicum of, well... Suspension of disbelief would be a fitting term, right?
My point is - there are three different kinks that can be very loosely labeled as bestiality:
1) actual animals and their look-alikes. I would reiterate that the core principle is that those are below their sentient partner;
1.5) kink on sentient animals exists too, in which it has to be both roughly IRL-looking animal and sentient being at the same time. Though, admittedly, it is a rarity compared to other three, IMO;
2) non-sentient mythical/fantastical creatures. This is called teratophilia (monster-loving) and here the difference in brains plays largely second role. Core principle is exotica of otherworldly often over the top (super-buffed, spikes everywhere, grotesque look, etc) partner that is impossible to find in real world;
3) sentient monsters. Its basically previous point, but here the core principle is that the partner is both monstrous and has more or less the same level of intelligence. Therefore, it has surprisingly little to do with bestiality, though it can and often does incorporate it.
Moral of the story - kinks are varied, they don't have strict boundaries, and it is silly to call something bestiality just because a thinking and talking partner happens to be quadruped.
I think that more accurate - and general - term would be xenophilia, which is precisely what dragon-fucking is.