Just looking for confirmation on my take on what seems an OP card. Deal 2 damage to all attacking units when this unit is defending alone, discard the unit at the end of turn. So once I play this in the action window after declaring my unit as the lone defender, I deal two damage immediately. Possibly killing all attackers before they actually attack? And if any do survive, I can still do normal damage in the apply damage step of the fight?

Any clarification on this would be great, I did this last night and felt like I was cheating, totally swung the game in my favor.

Assuming the unit has two power, your understanding is correct. How useful this effect is depends on the circumstances.

Thank you. Yes the unit had 2 power (4 hp's). The circumstances was 6 attackers, 4 of which had 2 or less life, so after playing Valour of Ages, there was only 2 attackers left (both ended up dying, one from a re-directed damage from a legend ability and the other from 2 unit damage). Just about perfect situation to play this card, and for free to boot!