Adding cards with abilities usually associated with another ink color would fill some big holes, especially when it comes to the ink ramp
You don't get to look at the cards in your library, but if you happen to know the position of a card in your library for example, you know what you scried to the bottom of your library with Opt, or you cast Approach of the Second Sun last turn you can use that to your advantage and make sure you draw it when you need to
Honorable Mention(?) Chromatic Lantern If youre paying a deck with more than one color of mana in it, then you should definitely be using Chromatic Lantern
"Dragon of Mount Gulg" will do nothing for that price, because as of this writing, "Dragon of Mount Gulg" is already the most expensive version of the card, going for around $150
One or two target creatures can't block this turn
Its power and toughness are equal to the number of Islands you control