Innistrad: Crimson Vow takes the dark monster-filled theming and makes it all centered around a crimson-filled night wedding between the two iconic Markov and Voldaren vampire families
The Duke gives you the Blade of Selves ability without the additional mana investment, which means they're all aggro all the time
Powerful token generation fueled by full graveyards makes The Scarab God a no-brainer for mill decks, but the tokens themselves frequently win games on their own merits
Ramp, then, is quite literally free real estate in more casual or social Commander environments
If you've already got a lot of cards from The First Chapter, apart from the guaranteed foils in the 2 decks, it might be more cost-effective to put your money towards boosters, unless you're looking to pick up the cards from either of the starter sets quickly, then the fixed nature of the decks will get you those quicker than randomized boosters
Crackling Drake A solid finisher when you are spent