Since you'll be gaining life very early on, you'll likely have a ton of excess life by the time you bring out Bolas's Citadel, as it does cost three generic and three Black Mana to play
I run this is the vast majority of my Blue Commander decks, since, unlike Rhystic Study, this is nice and no one will feel hurt with your taxes or massive card draw
In best-of-three matches, you can utilize these cards to make changes to your main deck between games
The level up keyword works at sorcery speed
While at first glance, Black and White may appear to be two of the most polar opposite colors in all of Magic: The Gathering, when working in conjunction, the colors bring a lot of power to the table
Getting to go on the offensive with him and then untap him for use as a dork is a nice bonus, as is the fact he becomes a land therefore untargetable by common removal