This DLC contains the hero attire: Warrior Mouse Attire
Liangyunic folklore tells of a mouse that bit through a string from which an oil lantern hung, setting fire to a barn and alerting the town watch to some bandits who were hiding therein. Warrior Mouse, as this rodent became known, was supposedly rescued from the wreckage and honoured for its bravery.
The above DLCs can be claimed by talking to the Town Crier in a capital or the Trade Colonies after purchase.
Note: This DLC contains a hero attire which only changes the wearer's appearance, not their attributes.