Cloudian - Acid Cloud (GLAS-EN010) [Gladiator's Assault]

This card cannot be destroyed by battle. If this card is in face-up Defense Position, destroy it. When you Normal Summon this card, place 1 Fog Counter on it for each "Cloudian" monster on the field. You can remove 2 Fog Counters from this card to destroy 1 Spell or Trap Card.