If this option is taken for any model in the army, then all models in the army that can take it must take it. When the model is removed as a casualty, place it in a Reinforcement Pool next to the Battlefield. At any time, you may remove 40 models from this Reinforcement Pool and place one of the following Summoned units in Tunnel Reserve:
• 25 Vermin Legionaries with a Champion, a Musician, a Standard Bearer with Eagle Standard, and Without Number. The unit loses Scoring. The unit may take Shield and Spear.
• 40 Vermin Slaves with a Musician and Without Number.