Frontline Medic

Text:

Battalion — Whenever Frontline Medic and at least two other creatures attack, creatures you control gain indestructible until end of turn.
Sacrifice Frontline Medic: Counter target spell with in its mana cost unless its controller pays .

Rulings:

• 4/15/2013 The three attacking creatures don’t have to be attacking the same player or planeswalker.
• 4/15/2013 Once a battalion ability has triggered, it doesn’t matter how many creatures are still attacking when that ability resolves.
• 4/15/2013 The effects of battalion abilities vary from card to card. Read each card carefully.
• 7/1/2013 Creatures that come under your control after Frontline Medic’s battalion ability resolves will not be granted indestructible by this effect.