Depending on how much you want to spend to optimize your land base and include tutors to search for these combo pieces, you could likely take this deck as high as level five
For two mana of any color, you can search your library for any dragon, discard it, and Scion of the Ur-Dragon becomes that dragon until the end of the turn
I recommend reading the flavor text out loud when you cast each Defeat
Advertisement Each player takes the top 7 cards of their deck and puts them in their hand
There are tons of cards to wade through and since not all of them work together, getting the harmony of your decks cards can take some time to assemble and get used to
However, I like the removal capabilities of Erebos, Bleak-Hearted that can then work with its draw abilities