Vedalken Shackles and Stormbreath Dragon Monstrous Trigger

[Khurtz]

I was recently playing cube with a friend when a situation came up wherein he swung with Stormbreath Dragon (not currently Monstrous) and then activated the ability after blockers were declared. I responded by stealing the dragon with Shackles. I know he controls the Monstrous ability and I'm assuming how this would work would be that it resolves, puts the counters on the dragon and then triggers the second ability, which I would control since I control Stormbreath Dragon at that point, then Stormbreath Dragon deals the damage to my friend. I wasn't entirely sure if the ability could resolve though since he no longer controls the dragon. Would the ability still add the counters to the dragon and give it monstrous under my control or would it be countered on resolution with an illegal target? Any insight into how this works would be greatly appreciated.

[Malchar]

Your opponent controls the activated ability ability ":5::r::r:: Monstrosity 3" while it is on the stack even if you steal the dragon because he was the one who activated it originally. Your opponent still has to follow all of the instructions for the monstrous activation even if he no longer controls the creature: "If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous."

Since you control the dragon when it becomes monstrous, you'll control the triggered ability "When Stormbreath Dragon becomes monstrous, it deals damage to each opponent equal to the number of cards in that player's hand." So, "each opponent" wouldn't refer to you; it would be all of your opponents.

None of these abilities will be countered due to having illegal targets because none of them have targets to begin with. The word "target" never appears on the card.

[Khurtz]

Thanks Malchar, that's what I suspected but I wasn't sure. I appreciate the help!