In the Declare Battle Formations step you can set up ASURYANI MOUNTED and VYPER units from your army in Reserves. During the battle, such units can be set up on the battlefield as if they were arriving from Strategic Reserves. For the purposes of setting up ASURYANI MOUNTED or VYPER units from your army on the battlefield, treat the current battle round number as being one higher than it actually is.
In addition, at the end of your opponent’s turn, you can select a number of ASURYANI MOUNTED or VYPER units from your army (excluding units within Engagement Range of one or more enemy units), then remove those units from the battlefield and place them into Strategic Reserves. The maximum number of units you can select depends on the battle size, as shown below.