Here

Dont worry
They are noobs like you at every walk who cant fucking find diablo clone in their games.... i dont know how they do it

He will spawn at the first Super Unique monster you encounter. So you can basically choose the location to fight Uber Diablo by selecting which Super Unique you want him to replace.

That's not true I killed eldritch after he walked then found him at the stones in stoney

If you've seen the super unique already in that game it won't replace him...or so it seems. its gotta be a superunique you haven't run into range of during that game. Most people spawn him at the same place, usually shenk, or perhaps threshsocket, or chaos sanc, or wherever they feel they can best fight him.

I was in a game where the server spawned him and he was nowhere to be found. Come with chat log ss to back it up. I brought 4 buddies in and we checked every super unique off the list - no uber d.

Stupid question, but, were you in Hell?

Ha fair question. I was, yes.

then someone spawned him there before you killed eldrich

Private passworded game with no log of anyone coming or going only thing I can think is that it's because I ran countess then trav then ran to get eldritch TP before parking in town to wait for the last 15 mins before spawn