At the end of your opponent’s turn, you can select a number of HERETIC ASTARTES TERMINATOR, OBLITERATORS and MUTILATORS units from your army (excluding units that are within Engagement Range of one or more enemy units). The maximum number of units you can select depends on the battle size, as follows:
Battle Size - Number of Units Incursion - Up to 1 unit Strike Force - Up to 2 units Onslaught Up - to 3 units
Once you have made your selections, remove those units from the battlefield and place them into Strategic Reserves.