I might be able to get away with playing The Mending of Dominaria without too many creatures because I can surveil the few I have into the graveyard
This destruction clause is also a solid hedge against traditional answers to stealing creatures like Homeward Path, as returning your stolen creature or having it stolen from you by someone else doesnt exempt it from being destroyed when Merieke leaves play
Nostalgia is a helluva drug
But I can also see her having potential in creature combo decks
The more niche you are as a card, the more you push toward the middle of rarity and away from the ends (common and mythic rare)
This blue instant also counters artifacts, Karn, etc., and also fizzles lots of stuff while replicating into Ashling triggers, which allows an Izzet deck to be pesky while converting into while rummaging/drawing three cards and dishing out a one-sided Pyroclasm