This sort of copying has been on Mew cards before and was all used effectively
By paying either blue or black, and then X mana, you get to pick a color and an opponent
Perhaps Amped Raptor, a new addition to the range of cascade-like effects, caught your eye
Not only is it a great creature removal spell that you dont mind firing off early (unlike Path to Exile where the extra land matters), but it covers problematic non-creatures too
You want to make sure youre resolving Eriettes ability first, that way regardless of if youre choosing feed or friends with Astarion, youll get more out of it
It is the least impactful fall set of the past five years in terms of cards played, while also creating the biggest jump in Standard deck prices and the most expensive Standard of the past five years