Gungeon

at some point in the campaign, a meteor crashes into the earth exposing a long forgotten dwarven and drow mining facility. The players traverse through the wreckage into mines and find the deeper they go in, the more grotesque the monsters become. The reason? The mines originally used a replica of the abomination crystals as power sources. The meteor stuck the machinery, causing parts of these crystals to get lodged into the beasts then roaming the mines. Can the players piece this together? Can they reach the depths of the mine to find the final replica?

And where did that meteor come from anyway?