This is the only mono-green mill deck you'll ever need
Generally, the value of a GX card can range anywhere from a few dollars to several hundred dollars or even more for particularly rare or sought-after cards
One of these first print Topsun Charizard cards realized $52,800 in a Fanatics Collect Premier auction in January 2023
This Rare Rainbow card is numbered 221/203 in the set
It does cost a fair bit of mana, but if you're playing a rad counter deck, you will be milling yourself so adding on a reanimator package can get it to the battlefield quicker
On top of that, I think Mono-Blue Aggro is actually pretty good against the current iterations of Esper Control, unlike in Ravnica Allegiance Standard where the matchup was a lot tougher and I valued having access to a planeswalker out of the sideboard, so Im not too invested in the idea of a dedicated sideboard card for that matchup anyway