Hunting the dangerous monsters Nicah is no easy task and each legion can endure only a certain amount of hunts. Each hunt, either it's won or lost, will result in your legions sustaining permanent damage.
Each hunt will reduce the total attack power of the legion usually by 2%. The damage percentage may be adjusted slightly based on the Omni-Balanced Oracle™.
The more hunts done by your legions over time, the weaker they will become, until their attack power reaches below 2000. Once a legion's attack power is below 2000, then you can mark the 'hide weak legions' checkbox to hide them from your inventory. The only way to replenish your legions will be by adding more warriors and beasts. However, keep in mind that you can only add more warriors and beasts until you reach 10 beasts per legion, and taking into account the maximum number of warriors that each beast can support.
If you don’t hunt with your legion, then it’s total attack power will not be reduced.
Once a legion is formed, it cannot be dismantled. It is not possible to remove warriors/beasts from a legion once they are inside it. The legion can only be executed as a whole. You can also choose to sell your legion in the marketplace.