One of the best black creatures, Blood Artist is an important source of repeated lifegain triggers for the decks that want it, as well as a win condition
though just two were included in that set, Reshiram and Zekrom, they proved popular enough that they continued to return in larger numbers, in subsequent sets
That, plus Start Playing Commander Here and the presence of a single foil mythic, tells me that this set of decks is all reprints
Mulligans in Constructed Constructed is where you'll want to deviate from the "Two to Five Lands Strategy," because games are faster, decks are more powerful, and you're punished more quickly for keeping a sub-par opening hand
A few designs come about because you're trying to prove something
but since this guide for absolute beginners, here is a very basic anatomy of a basic Pokemon card