Chasm Skulker both wants to have lots of card drawing but also make use of a lot of little 1/1 token creatures
Awaken the Honored Dead Sagas like Awaken the Honored Dead that have removal in the first chapter normally see play
At that time, there weren't enough Learn cards to justify Lessons taking up sideboard slots, either
The biggest planeswalkers like Karn Liberated and Ugin, the Spirit Dragon
Herere the rares in order of awesomeness: Some of the uncommons are quite cool, too, so I want to highlight a few of them: Blacksmith's Talent, which drops two rectangles for one mana and which will be great in certain sacrifice decks
His first articles on mulligans (here and here) started a trend on the topic, and theres a lot of good stuff in his archives