The reason the Ether Dragon hatchling attacked Deathwing wasn't because it was interested in the Continent of Azeroth or any battle between good and evil, but for a much simpler reason.
As previously mentioned, Ether Dragons grow by devouring Stellar Energy, and when Deathwing reappeared in the Boundary, it happened to be in the Ether Dragon hatchling's vision. To the hatchling, this flaming and glowing entity seemed very much like the food it consumed!
Wonder if it tastes good?
Driven by the instinct to bite when curious, the Ether Dragon hatchling took a bite out of Deathwing.
And that was the end of that.
It was a complete dimensional reduction strike; after all, Deathwing is just a Giant Dragon wreaking havoc on the planet, unable to compete with the Ether Dragon that casually roams the Universe.
