Most successful blink lists run roughly 12-15 blink effects (mix of instants and repeatable engines) and 15-20 ETB creatures
Everything is always changing and the game is always morphing
Typically, you dont want to risk your valuable planeswalkers by opening them up to removal in combat or by Murders, but there are some goofy things you can do with this
The biggest feature is the promo cards, though, because Alternate Arts have been by far the most popular feature in the Sword & Shield series block
Winning Worlds once is a monumental achievement by itself, but there are only two players who have ever won multiple times--and not just twice, but three times each
BPhillipYork: Yes, more "Ugin" cards that get slammed into Eldrazi decks