Older Sword & Shield cards from the S6K Jet-Black Geist era use the SA designation (Shadow Rider Calyrex VMAX Alt Art, Chubby Blissey V Alt Art) rather than the later SAR letter code, but theyre functionally identical in the alt-art collecting lane
Throw in an excellent card sorting and searching tool, as well as the ability to create and modify decks quickly and easily, and even the pickiest of card collectors should be pleased
Alternatively, it may be a combination of retsu (violent or furious), k (sky), and za (seat or location), which can be taken to mean "one that sits in the ferocious heavens"
It might therefore be prudent to expect Innistrad: Crimson Vow's EDH decks to include few, if any such cards
Shield counters act like temporary totems - surviving board wipes, combat, and pesky removal spells