The reason for this is mainly that since the printing of Ragavan, Nimble Pilferer, Dragons Rage Channeler and Murktide Regent the tempo archetype reinvented itself in being primarily blue-red and making Deaths Shadow not a necessary creature for tempo shells anymore
If you are not super comfortable with that just yet, you will want to identify what exactly your decks goal is before you begin building
Shadows on the ground indicate where theyll land
And we also have conceptual matches like Wall of Swords for the spell Blade Barrier, Chill Touch in D&D which drains spirit and soul vs Touch of Death, Return to Sand vs Return to Dust, Anti-Magic Aura vs Anti-Magic Shell, etc
The guaranteed floor is solid: every single box gives you 1 Trainer SR, 3 ARs, and 4-5 RRs