lets destroy the sun

[Crake]

I know it was discussed and likely rejected on the first page, but opening a gate in the middle of the sun would do it, and you can take out a plane of your preference in the process! The intense gravity of the sun would cause an immense amount of super-dense material to flow through the gate for its short duration, and while it won't be enough to wink out the sun, it will probably be more than enough to reduce the sun's mass by enough to trigger a supernova.
For those confused, the sun's huge mass is keeping its own explosive force from doing just that, exploding. If you can take out enough of its mass, especially from its superdense core, you'll reduce its gravity enough that it will just simply explode as its explosive force becomes greater than its implosive force.

Now the question becomes not how to destroy the sun, but rather do you want the earth intact, and if you do, how do you plan on going about protecting it from a supernova.

The other option is to go the opposite way and produce enough material to have the sun collapse into a black hole. That one would take a lot more time though. Of course.... once you've got the sun collapsed into a black hole........... its then easy enough to engulf it in a sphere of annihilation. Need to do that before tidal forces rip apart the planet though.