Look, I'm not here to sing Overlord's 2 (By Triumph Games) high praise for the romance department, because while yes it's all heavily femdom coded the whole thing is still framed as a 1 on 3 Harem of Trophy Wives (Which works on Juno and maybe Ghost Fae yes but Kelda? DARK FAE???) whose personalities are highly archetypal ala Harem Anime (We have the Phisically Strong Childhood Best Friend, Wolf Coded, the Spoiled Rich Temptress, Spider Coded, and either the Chad Dominatrix Evil Faery Queen or the Virgin Sub Ghost Faery Queen, Salamander Coded), and still end with a pretty heteronormative foursome.
But still, The idea of the whole thing, however, has incredible potential if we slowly shift from all of that, give each mistress more of a role in the conquest, a more nuanced backstory and personality, and ALSO remove the coding and turn to outright femdom.
Kelda can become easily your huntress or general (mayve you get to decide what role each can do in the tower), Juno a spy mistress, or a poisoner, and so on, but if you let them laze around as they please they gain Higher Affection toward you and might depending on the character decide to do some pet projects instead.
Come on, it's a Hades and Persephone scenario, but Hades is on a 3 to 1 numerical disadvantage, and the 3 Persephones, after a rough start, end up liking each other AND shoulder the burden of rule with him (Unlike the unfortunate actual ending where Kelda is still pretty pissy over getting her role as Top Wolf challenged) and all that.
Maybe have each of them channel the spirit of the Queen of each mount? The 1st Overlord slew the Wolf Queen so Kelda is fixed from the start, then you, the 4th, kill Spider and Salamander Queens for the other two.
Maybe add a 4th mistress for the Blues. We have giant toads show up at sone point yet we never use them for the Blues? Why are the medics the only ones without mounts? Repurpose Ghost Fay for that, somehow? Split Persobalities maybe, ala Harley Quinn in Vampire the Masquerade, but the dying personality turns into a Ghost, That way you still have the "moral" choice?