sitting in private hell game - can someone remind me how i go about locating the clone once it spawns? - ty

he will spawn at the first unique mob u come across

The first unique u find turns into him

It's more like he finds you. Just go look for a super unique (not any unique mob) and he'll be there.

eldritch is easiest

For sure. If I know the game I'm in is going to be hot and spawn Uber Diablo, I actively avoid Frigid Highlands WP so that I can just jump in there and get him when the time comes.

Make sure that you don't trigger the super unique you want him to spawn at until you see the message that Diablo has invaded. Otherwise it will be time to find another super unique candidate.