In the games it's capable of creating Eggs (the birth of which Cynthia claims "no one has ever seen before") and according to its myths it can create entire worlds and existed before all else.
In the 12th movie they described it as being able to "create entire worlds" and with the Plates it can nullify any attack. With all of its Plates it's likely all of the attacks used against it (even possibly Palkia's ability to hold it temporarily in some space bubble) wouldn't have had any effect.
So, probably? Like
>>15322313 said there's probably not even an "official" ruling on that. They try to avoid such things (except, oddly, calling Kyurem "the world's strongest Dragon").
