Cosmogrand Zenith If you want a card that rewards you for casting multiple spells a turn, Cosmogrand Zenith is perfect
There's a lot of staples for Counters decks here, like Inspiring Call, Inexorable Tide, Hardened Scales, and it's the first time we've seen Damning Verdict reprinted, one of the best cards for a Counters deck as a one-sided wipe and it was quite expensive for that reason
Just like Eternal Witness is usually more powerful that Regrowth because you can abuse the creatureness of it, you can flicker, bounce, or recur this for more and more lands (maybe even cards!)
6 Encore Electromancer - Snapcaster Mage - Secret Lair Drop Series Mythic Rare - $729.93 An incredibly rare card, this special Hatsune Miku version of Snapcaster Mage was a bonus card that had a very low chance of coming in Secret Lairs which were released in collaboration with the vocaloid Hatsune Miku
A mana dork that adds two and lets you cast from the yard is great, and menace is even better for triggering treasure generation from attacking or dealing damage
This combination of tones is a fantastic match for Magic: The Gathering
