Originally Posted by
Exxord
Ok Blizz, let's try to fix this.
You send your little npc party to a mission, and when they have done with all the minions and are before the last boss they will contact you and wait for your orders. You can call them back with all the loot and xp they got from the first part of the mission, or they can summon you to try to kill the boss for some big extra reward. In this case, you (solo or with a couple of friends) will partecipate in a short scenario where you will fight a raid-like boss alongside your npc followers. If you lose this fight, you don't get any reward and your followers won't level up and have to pay some currency to revive your allies.
Now do it.