This means that based on a player's choice of commander, they will have access to different types of cards, meaning differing color identities have their own strengths and weaknesses players should acknowledge when determining their deck's commander
For example, if you control Johann, Apprentice Sorcerer ("Once each turn, you may cast an instant or sorcery spell from the top of your library.") and Questing Druid is on top of your library, you can cast Seek the Beast, but not Questing Druid
Specialize allows the player to pay mana and discard a color/land type of your choice to change your card to that new card with its effects (the change depends on which color you discarded)
Blaine (Pokemon Japanese Challenge from the Darkness | Pokemon Cards) prices are based on the historic sales
Profane Command Black Fear Sorcery [c]Profane Command[/c]s power lies in its versatility
Creatures (16) Planeswalkers (6) Lands (24) Spells (14) Joses list definitely tries to exploit how much less removal people were playing maindeck (not wanting it to get stranded against U/W or line up wrong)