ToME: the Tales of Maj'Eyal

I have a level 23 archer on a rouge-like nightmare run. He is currently in the temporal rift in an endless battle with the Chronolith Twin.

The twin has 78% resist physical and 23% resist all. Kinetic shield, Charged shield and a rune damage shield to boot.That would all be fine if he couldn't wall himself in stone or teleport away and use realign to heal himself. The only damage penetration I could scrounge out of my inventory was an old bow with 11% resist all penetration. Nothing close enough to what I need.

He can't kill me either, so we're in a battle stuck in time for all time.

Any suggestions? Am I SOL on this run?

Yeah, you're probably boned.

That's a little low level to tackle that area, given the possibility to run into precisely what you ran into. Maybe you can get lucky but probably not.

Have you killed the other one yet?

Yes, I was able to kill the other clone pretty easily. The twin however remains.

My character and the Clone will battle for all eternity I suppose. I never came up with a solution.

Yeah that happens sometimes.
It helps to carefully check which clone is stronger, as they partly share damage.
This means that you can leverage that to help kill the tougher one, but also means that you can inadvertently kill the weaker one too fast.