450 runs 80% barb/20% nec.

Ubers only found with Barb:

doom
shako
doom
grandfather

got it on my lvl 43 rogue

1500 runs on necro never got doom bringer ended up getting doom bringer after 50 runs on my barb

i think doombringer only drops for rogue and barb

I think swapping between Barb and necro is best tactic. It seems the logic gets stuck trying to drop Azurewrath on barb and won't drop any other sword. I had about 6 out of 10 Azurewrath drop one night on barb, swapped to necro and finally got GF after 6 runs or so.

Got Doombringer finally.

Summary: 600-700 runs total, all on Barb, 2 GF, 1 Shako, 1 Selig, 1 Andy, 1 Doombringer

Not sure if it's related, all drops are from solo run, or when I'm the mat provider. Dropped nothing from 300+ runs that are rotation.

I figured under current mat price, solo run is very efficient, can even not pick trash loots. Only night can run 200-300 runs.