You have a 4/4, unblockable, untargetable, lifelink body that will be hitting for four damage and you will get four life as well, for an eight life swing
You can, and probably will run your mundane mana rocks, but artifact decks have access to a host of powerful cost reducers that work exceptionally well with broken combo strategies
The draft environment is all about playing to the board, so you need to prioritize good creatures and better removal
Annex doesnt affect the board in a meaningful way, but youre gaining a land and your opponent is losing one
However, Urborg is the sort of card I only expected Wizards to print once
Casting a fight spell and targeting it to fight an opponents creature could end up with killing that creature and also killing Draconic Muralists , allowing you to search your deck for a Dragon card