The alert icon refers to all active Yields (see Tips and Tricks) its greyed out when there are no active yields
One of the three cards will ALWAYS be a special Holo Pikachu promo (#SWSH039, pictured right) This Pikachu card is the only card in the General Mills promotion to have the special Pokmon 25 stamp
In theory, we could play Evolving Wilds or a tapped dual land like Swiftwater Cliffs, which would make the mana more consistent but at the cost of giving us a lot of tapped duals
If you're confused about when the various MTG sets are coming out, check out our MTG release schedule guide
Before Magic Origins , menace was virtually around as text on cards that said, This creature cannot be blocked by only one creature or This creature cant be blocked except by two or more creatures
I hope this helped you think about how you might incorporate some of these cards into your next brews