Thanks to Dark Ritu uh Thought Scour, the big Dragon can show up as early as turn two, but will commonly show up around turn four with Counterspell to protect it
If one of the cards you go get is Seasons Past, you can get back basically anything you discarded, whatever you tutored for, and the Behold the Beyond, surprisingly doesnt exile itself
Crucible of the Spirit Dragon [Dragon Deck]: Makes sense to include it in a dragon deck
Besides being a rather handsome critter that uses a sonic blast instead of fire-breath, it should come in handy thanks to its ability to let you scry 2 whenever you attack or block
These are vastly superior to the Case of the Uneaten Feast effects because they count your opponents creatures as well
Color Identity Your deck can only contain cards whose color identity fits within your commanders color identity