The Manticore fell only three minutes after the giant worm had, its body scorched nearly unrecognizable by Hawk's flames, but the Earth Golem was still going strong, so Karl had Opal spread [Illusionary Domain] as far in Dana's direction as she could.
Once that boss was dead, they would conjure an army of Dwarves to mine out the dungeon, sweeping the area with [Illusionary Domain] as they went so that the dwarves could travel the entire dungeon looking for resources that the rest of them might have missed.
There was no rule about preparing in advance, only that they weren't supposed to start mining until all the bosses were down.
The Elders of the Yizimon Clan sensed the change as two of the three bosses died within minutes of each other, and shared a concerned glance as they calculated the resources that they were going to get out of this dungeon.
