Got black demons for the first time on my 200th task, which was a nice surprise. I decided to range them in Edge dungeon, since I had been there before with Baccannis, and I knew the range spot. There are a few places where they can easily be ranged, and sometimes it is necessary to move between them.
Occasionally a rev comes, but they are usually too low levelled to attack.
They usually just drop coins, but have a chance of dropping rarer rune items.