The reason I think a relationship with Overlord might not last long depending purely on how well you catch his interest is due to a quote of his, said quote being this one:
He is very easily bored and lives for fighting, something Megatron thought was an act. So with that in mind, to be Overlord's lover or catch his interest romantically (or garner his obsession) one has to know how to fight and be skilled at it. Said s/o also can't back down, you would be boring in his optics if you do, he loves you for the challenge you offer, for your wit, for your skills, he cares little about frame type and allegiances. Everything else comes last.
To sum it up in my eyes the main reason he'd be with you isn't for you, it's for your skills. Your skills are the thing that attracts him the most, not your personality at first. I say at first as depending how his interest in you develops as does the chances of him liking you more for then just your fighting skills. If you can hold your own against him and possibly even be on par with him he'll notice the small things about you, he'll finally pick up on your intellect.
So due to that I can't really see him with anyone who isn't a capable fighter and strategist, to fully catch his interest you must be both. While on their own he would still find you interesting, especially if you can use one to beat him I feel he'd still prefer it or be more interested if you're both. He wants someone like him, a talented fighter who's also a great strategist so they could be on his level and hold their own.
But that's just me, idk if others share the view, this is simply my view as said and part of how I characterize him to a degree at least, his characterization and dynamics have many factors in my eyes... but I'll save that for later.
