At the end of the Taken strike in the EDZ there's some supposedly "big reveal" that the boss is Red Legion. Leading to this conversation like, "Oh, how'd he get Taken if Oryx is dead? It must have been one of Oryx's sisters that's started getting all Took-y."
Oryx had been Taking civilizations for thousands of years before his defeat. Maybe millions. I forget. Is it somehow inconceivable that in all that time Oryx never ran into the Red Legion, a military force with a supposedly galactic presence? Makes more sense to me than one of Oryx's sisters Taking cabal in our solar system from whatever far off dimension they occupy.
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The Hive don't "run into" other species. They annihilate them. In every war the Hive have started in their long history they have always driven their opponents to extinction. That's why it's such a big deal for us to have stopped the Hive's efforts and killed Oryx, and that's how we know the Cabal have never met the Hive before. If they had the Hive would have fought them to the end because withdrawing from a war would show weakness and allow their worms to devour them. Also it's hinted in other parts of Destiny 2 that Savathun is making her own Taken so that end revelation in the strike is obviously true.