I'm sorry if I come across more aggressive than necessary. It's definitely not my intent. >///<
Thank you! In fact, that was one of the important things that I had to navigate so as to keep the interaction between them believable. That is to say, Ganondorf's ego. Like, I had to really thread the needle on keeping her his equal, while not bruising his ego too roughly. Mostly, I did this by having it so that she starts off as equally skilled as him, but lacking in physical strength thus allowing him to just barely win their spars. At least, until after he's caught feelings & they're married. After that, she'll eventually become so evenly matched with him that spars become more a matter of luck & strategy than prowess. And I'm referring to both of them.
Another important factor for them actually being able to work together is that her personality is far more humble, level-headed, & self-assured than him. She feels no need to behave dominantly, so Ganondorf doesn't feel threatened by her. More so, she is a very composed individual with a presence of gentle authority that goes unspoken until she shows exactly why no one should ever underestimate her. (Though, it's sometimes difficult avoiding the Mary Sue pitfalls.)
Really? Then, we must not run in all the same fandom circles as I actually don't tend to come across this trope much in my own fandoms, which is part of why I find the silk hiding steel trope to be such an interesting one. Though, I wouldn't be shocked if it's actually more common than I think & I just haven't been encountering it. At the same time, that's EXACTLY the dynamic I had in mind: the yin to his yang!
Oh? I- Thank you! That's very kind of you! >////< Though, would you mind reminding me what, specifically, I wrote on ALttP Ganon that you enjoyed, as… I've kind of made a bunch of posts. 😅
As for your question, in the end, I somewhat see the Beast Ganons as Ganondorf losing himself. Not simply his humanity, but in some cases, his sanity as well. Maybe not so much TP & HW Beast Ganon (as, for whatever reason, they give the impression of having greater control over themselves), but definitely in the cases of OoT, TotK (referring to Dragondorf), & especially with the Beast Ganon as he's depicted in the Downfall Timeline. Though, I base that last part on the fact that by the time you see him in LoZ2 (I believe), he's essentially little more than a non-verbal, vaguely anthropomorphic pig-shaped silhouette that really just... doesn't seem to react much.
And, I somewhat use that alongside other bits & pieces of information throughout the series, to put together what I hc the actual consequences of using black magic (such as malice, gloom, & the like) to be. In my mind, it's corrosive in almost every sense of the word & the ultimate end result for warlocks/witches (those who use it) is to eventually become monsters. Some even little more than animals mentally. In a way, you could see it as having a similar effect to that of the Ring from Lord of the Rings. It grants great power, but at the cost of losing everything.
But I digress; in a sense, I see Beast Ganon as Ganondorf's swan song &, in some respects, even a monument to his own hubris.
As for how they'd take to my OC... It would vary greatly depending on not only the Beast Ganon, but also the version of my OC that would correspond with that Beast Ganon, as well as how far along in the relationship the 2 would be at those times. I'm more than willing to give it a good think, but it'll take time.