The Borg cube would find the inherent flaw in the Death Star and exploit it. Borg cubes can’t be destroyed easily just through weapons fire because they’re self-repairing and have adaptive shielding.

I guess even if the Death Star were able to destroy a single Borg Cube, that would be it at most.

I would say so. Also, Borg Cubes are decentralized, which makes them harder to cripple, let alone destroy.

Well, the Death Star can destroy a planet, so I’m thinking they could take out a single cube.

Imagine the energy required to destroy a planet…

But if there’s more than one cube, I’m guessing they’re fucked.

But what happens if Vader were assimilated?

We haven’t seen the Borg using generic engineering AFAICR, but it seems like something they would do. Assuming midichlorians are canon, I think the Borg could discover and replicate them. Surely one of the species they assimilated had bioengineering mastered.

that was basically the plot of Star Wars: The Bad Batch.

The best geneticists in the universe (the same who make the clones) couldn’t, but they were getting close, in theory. Could the borg? Maybe. Eventually.