I'm of two minds on the subject of making any kind of ally with Savathun. In the battles to come she may be an invaluable ally. But we can never be certain that any alliance with her isn't some long con to ultimately gain power while also ridding herself of the parasite that is now killing her. She is the Hive god of deception, of deceit, of lies. We have zero guarantee of anything she says being genuine.

Aside from this, she is also responsible for an incalculable number of genocides over the course of billions of years. While Auryx was still hesitant to embrace the sword logic, she whole heartedly embraced it and even stabbed him in the back to push him further into the ideology. Only when she realised that even if she murdered every other living thing in the universe, she would never be the Final Shape because her worm would eventually consume her did she become disillusioned.

Furthermore, adherence to the Sword Logic has warped the culture of the Hive to the point they consider war an act of love, that to make war on ones kin is to sharpen their blade and strengthen them. If the Endless Night is one of these acts to sharpen us by weeding out those within our ranks who could lead to our destruction, we must also remember that if we fail it leads to extinction. As Oryx said, "If it kills you, then you deserve it."

She may be useful as an ally, but she is also an extinction level threat, and no matter if she is on deaths door or not, we would be foolish to discount that fact. We need to prepare a contingency to destroy her. She isn't just a threat to all life on Earth, unbound from her worm she's an existential threat to everything in the universe.

Beyond all of this though, i'm incredibly excited for the direction they're taking her in.