...oath makes him get Eidolon and everybody and drag them there before he can try putting it in a really big sun.

It does! But the sun is actually less good at destroying it than the black hole was.

He grabs everybody and puts them where the thing is, again, and then reports this.

It doesn't seem to ever come back to the same place, and its initial impact is always worse than the continued time after it goes. What happens if you teleport it to somewhere less inhabited, or try to teleport the civilians away?

And what did you and the other Elves get while you were in the time field?

Ended abruptly after only two days and most of them are dead, I'll bring them back and ask but it should wait until he's gone -

Teleporting civilians away - 

Meanwhile Eidolon tries tying the monster down again.

And after enough civilians have been teleported away the monster—escalates.

Unable to teleport while tied to the capes, it starts scrunching space everywhere. The effect is headache-inducing, with lensing everywhere and buildings being destroyed, capes being turned inside out or crushed—

He can pop around tap healing but it isn't fast enough half the time -

- stupid evil thing - 

- what if he tries teleporting chunks of it off to a black hole -

Chunks of it go!

...and then it makes a time field appear around them and they regenerate in seconds.

Chunks and an effort at diving into the time field?

The field winks out before he can do that.

But does that mean it can't regenerate -

Yes.

Wait, no, it twisted space to start regenerating without Epic being in the field.

Ugh. What if he tears it in half and drops half in a black hole -

He cannot tear it in half. A bunch of its body goes but the core stays, and even without the time fields that part of its body regenerates fast enough for the eye to see.

Aaaargh. He will tear chunks as big as he can manage, and hover, and hate the stupid thing.

The stupid thing does not seem keen to express emotions. It will keep trying to crush enough capes that it can safely teleport away.

Can he go round up more capes for the fight from anywhere -

There are some volunteers but most don't feel like they can help much or are already there.

...there is this one not-quite-cape he could perhaps try...

No, Scion's evil, he shouldn't do anything lest it provoke him to end the world early, before they have time to fix it, this evil thing could kill this whole world and that'd still be less bad...

Well, then the fight will continue!

Stupid evil thing.

Eidolon is one of the few capes managing to actually consistently damage it.

Legend is another.

Epic—can you find Scion? I think we'll need him—we've damaged this thing more than we'd ever damaged Behemoth and it's still going.