Metagame Balancing through cards vs nerfing

TIMEWARP

Dear Devs,
Would you please consider adding good but not broken metagame controlling cards to PMA-style sets that never rotate out? That way, players will always have access to answers to silly broken stuff, at the cost of having to dedicate a card slot to them. Thinking about stuff like Spyglass and Lavinia, Azorius Renegade. Not Test of Talents level of blocking. Healthier for the metagame than having to nerf cards in the future.