riftbound: league of legends tcg: origins - booster box Riftbound Chinese Slim and Product type at a glanceThis Slim display contains 24 Booster Packs with 5 cards each Riftbound League of Legends Trading

Then the player can special summon a monster with "Shining Sarcophagus" in it's text while increasing it's level by the number of cards destroyed by this effect

The decision to give this archetype its own structure deck in 2014 was almost an inevitability, and one that not only provided enticing reprints for general players, but also enhanced the decks fundamental core strategy and elevated it to new heights

No necromancer should be caught unprepared

I have a basic frame using Amethyst only, which you can see at Dreamborn

So perhaps there's a mix of reasons: WotC wants to address player fatigue, decides to make less precons, WotC also wants to nudge new players into Standard rather than Commander, Between new and returning players, UB sets have more traction among returning players , who are less likely to need a precon to jump back into the fray