Just far too slow to be useful removal and far too low power when not killing things
Of course in order to have a big impact youll have to have planeswalkers with lots of loyalty to spare (looking at you Karn Liberated, Ugin, the Spirit Dragon, and Nicol Bolas, God-Pharaoh) or have a surplus amount of them
Top 10 OP09 Emperors in the New World THE TOP 10 The rarest One Piece TCG cards from Emporers in the New World at a glance
It does OK with some enchantments, it works well with lots of dorks, no dorks at all or recursive dorks
It means that the sets were always meant to be played together, in which case Magic: The Gatherings old block format of drafts, where you'd take two from one set and one from the other, would have been more logical