My personal favorite is still the Mystical Archive because it felt good in Limited formats (mainly being answers, not threats, but still interesting) and some spicy old cards like Channel included
This is why it can be tricky trying to predict the values of cards before a set is out in the wild, as you never know which cards will get pulled into relevance
Teferis Protection White is spoiled for choice when it comes to protection spells, and even some of the cheaper options like Eerie Interlude and Your Temple is Under Attack are more than playable
While this looks like it wont hose nearly as many decks, if there is any deck that does a lot of escaping, this will make their deck useless
Three mana is a tad on the expensive side given that you also need to pay the cost of the spell you flashback, but its still doable
It reads, At the beginning of combat on your turn, create a token thats a copy of equipped creature, except the token isnt legendary if equipped creature is legendary