The boss battles would be simple 2,3 or 4 players vs 1 overpowered enemy , boss fights would have 2 stages and drops would be crystals ,a rune (based on the boss bg theme) , gold or Rune packs. What you think about it ?
While I could see some 2 player campaigns where they make a lobby about it, I'm not really sure how to design the idea. It's not a bad idea, I just don't know how they would go about it, especially if it goes beyond more than two players.
Maybe just keep it at 2 players for a boss fight. For now at least. But I would be very interested in this concept!