This is ridiculous.

The Equestrians grow more powerful
Good, I think, no problem with people being powerful

The Equestrians take Void Humans into their nation.
Fine, I think, he created them after all

They make an Equiis pact
Alright, I think, bit weird how the Equestrians seem to become defacto ruler of a union of species and how they have humans... I suppose as long as keyguy is fine with this, after all humans are his

They start research and construction
Nothing wrong with competition I think

They absorb a species that essentially completely makes my nation irrelevant and is essentially the exact same thing just without a mouth (Which it now has, so there is like, what, a few inch height difference only?) and pretty much assumes their position, just under the dominance of the Equestrians
Really? That's just being cruel. I thought the idea of this was to create interesting nations, not to absorb the species someone else species is based off and take what gives them something different. When did I ever do that with the Equestrians? Should I just go absorb a species with a powerful god and really strong magic skills or something? Of course not, because that would be the equivalent of saying "Screw you" just because you feel the need for traits
I toned down their psionic ability massively once Rogue complained, despite getting minor magic from the Selkath I never did anything to try and take magical dominance from the Equestrians and despite having free reign over what I absorb I've never decided to go absorb some random human clone, some random Sazkarjhit clone etc. Each species has their own traits, and I think we should respect that and not go grabbing carbon copies of other players species. I just think this is completely uncalled for, wrong and generally annoying.