Nope. You can only play an interrupt when you are given initiative in battle, either by numbers, or by special ability. So if my 10/10 hero goes out and your 1/1 king blocks and plays Hunger, my guy in battle is still winning, but all of my other heroes are dying (assuming their toughness is 6 or less). The heroes in territory aren't discarded until the end of the battle though, so if the hero in battle ever does get initiative and has a card to negate Hunger, the other heroes would survive.
EDIT: Instaposted. I guess I'm not faster than lightning. Or ninjas. Or at least not the combination of the two.
