Very well!
Keeping with your theme of Dragon month, id like to see Dragon-Ponyard reveling in new-found power. (optional: A very frightened Skyrocket observing)
However, ponyard has a bit of a lust for power, so his expression would be one of twisted satisfaction. he would most likely be laughing quietly. Ponyard has had to fight for his life since he was a child, and scars that wouldnt show on his pony form are quite obvious on a dragons body. He is almost litteraly covered in them.
In place of a unicorns horn he has two over-sized magical gauntlets that channel his magics.
Deathwing is one scary Moe'suckra. His hatred is so powerful its actually tearing him apart physically.