I decided to use priest + warlock for a brawl. I had these two cards on the board. I attacked a minion with the mistress of pain and proceeded to take 30 damage, 1 at a time.
I'm assuming this is because the mistress wants to heal you so badly that she keeps trying to do it, even though it isn't working. =P
It happens because when mistress tries to heal you, it does damage, and whenever it deals damage, it tries to heal. Thus it loops infinitely until you die.
Not until you die. 62 times.
Then, for absolutely no mechanically sound reason -- it stops... Fatigue warriors have been known to survive and winning games where they got the combo against them (through Piloted Shredder dropping Mistress and their Sylvanas stealing Auchenai) because of the fact.
It always looked like a bugged mechanic, and the 61 repetitions (on top of the initial trigger) limit just reinforces that idea -- when warriors pretty damn easily can get 33+ armor on top of 30 health.
It IS bugged, one way or the other.
I think Blizzard's confirmed it's not a bugged reaction, though the dealing 'only' 61 damage may be an oversight. I'm sure they have some limit programmed in so the game doesn't get stuck in an infinite loop (e.g. if for whatever reason the damage wasn't being dealt properly but the combo was still triggering making the game unable to end) and chose 61 thinking it was high enough (I assume feeling absurdly high numbers such as 10,000 would be unnecessary overkill).