With monoliths, Skytear Games introduced a new system to set the difficulty level of Skytear Horde games.
Each horde card has now 3 variations with 3 different power levels, indicated by a color at the bottom of their card.
This system allows you to tweak the difficulty, and even the consistency, of the horde deck by selecting cards with 1 or 2 specific power levels out of the 3 available.
The challenge expansion makes it possible to use this system with the original 4 hordes. It basically contains 2 variations of every non-mythic horde card from the original Skytear Horde games.
Mythic cards are an exception where they only have 1 version which is always strong.
This pack includes 80 horde cards to play the 4 hordes from the original Skytear Horde game using the new difficulty system.