Prediction: Circulus is near unplayable now.
Between Mana Deathgrip, Abyssian’s endless pings, neutral options in Bloodtear Alchemist & Skorn, now able to be killed by Rasha’s Curse, Battle Panddo, Ghost Lightning, etc… every faction has an easy answer to it. And because it’s such a big threat when left alive, people will 100% tech these cards into their decks (though some of these cards don’t even need to be teched in, they’re already apart of most decks).
Technically Circulus can still be combo’d with Owlbeast and spells late game, but IMO the biggest problem with Circulus was T1 Circulus to threaten mana -> T2 CC, Aspect, or Flash Freeze + 2-4 mana play for no card advantage loss -> T3 Game already completely snowballed.
This nerf also significantly weakens the player 2 Circulus on mana tile plays. Previously, you could P2 T1 Circulus on mana tile + Frigid Corona or CC + Flash Freeze the opponent’s minion. You can still do that now, but it’s a horrible tempo loss since the Circulus will just die to a minion or general or ping in either case.
Because of these significant weaknesses I will be surprised if Circulus continues to be played in a meta filled with easy pings. And personally I think Arcanyst Vanar is going to take a huge blow because it can’t sustain it’s CC+Mana Deathgrip+3000 other spell plays without Circulus refilling the hand. I could be wrong here, of course, since Trinity Wing & Blue Conjurer still exist. At the very least however I think this will eliminate the stupid early game blowouts & snowballing that Arcanyst Vanar could pull off.