Omnath, Locus of Creation is a powerful new Landfall commander: generating insane mana is as easy as playing + cracking a fetchland, and one more landfall trigger is some serious damage that will make any Superfriends deck cry
Unfortunately, Guardians Rising was an unpopular expansion when it released due to having nothing exciting to pull aside these Energy cards
So you want some number of difficult-to-answer cards that naturally line up well against their removal, which can help close out games once the initial aggression is handled by them
This is pretty straightforward stuff, with the sort of distribution were used to: guaranteed foils of the new sweet lands, guaranteed foils of commons and uncommons in the new frames, a guaranteed foil rare or mythic, an extended-art version of the Commander rares (nonfoil only, a choice I still dont understand) and then the last slot, where the rarest, shiniest things live