"The Land Of A Thousand Dragons" (Standard)

you may want to add in some small creatures just so you don't get killed hard on the first 4 turns

Or some direct damage, like Lightning Bolt, to kill the opponents creatures. It's not even the first 4 turns, but the first creature will get into play at turn 6. Any deck that's any kind of good will have you killed by then or will kill you soon, since you haven't removed any of their creatures or other permanents.

Dragon Whelp might be not as good as some of the other dragons, but is out on turn 4. Dragon Fodder is somewhat theme related and helps you block a bit. Savage Lands, Jund Panorama, Terramorphic Expanse to fix your mana a bit, so you can have a bit fewer lands. M10 duals or Zendikar fetch lands even better, but more expensive of course.

Malfegor might be wrecking your eventual game, since you probably will have a lot of cards in your hand at the time you get it out into play.

WHAT?! No Breath of Malfegor?! It's Sizzle...but better

Terminate would help quite a bit too.

With the Dragon's Herald, you have to sacrifice three separate creatures. Your least expensive creature for green is either Broodmate Dragon or a Dragon Broodmother token, and your least expensive creature for black is either Broodmate Dragon or Malfegor. Is it really worth sacrificing such expensive creatures to get the Hellkite Overlord out?

Finally, to make it quicker, perhaps add in some mana ramp, such as Harrow and/or Rampant Growth.