Pull Rates: Understanding pull rates will help you make the right choice if you're hunting for a specific card
This is far better in a pure ramp deck where you will much more reliably have spare lands and resources to throw away or perhaps more need of dealing with specific things
Legendary cards make for fun pulls anyway, but Christopher Robin is exciting because of the deckbuilding opportunities it presents
It drops the cost of Dragon spells by 1 mana, and then, when it is on the field, your dragons essentially multiply as they attack
Let us not forget that the Kamigawa block has some great staples ( Gifts Ungiven , Sensei's Divining Top , Umezawa's Jitte ) and some of the most flavorful cards ( Marrow Gnawer )
Unfortunately, its unfinished, and in a way, its got a beauty that others will never have because to me its an unfinished painting for an unfinished life