Its a limit break to Magics design spacean explosive blend of nostalgia, mechanics, and power that reshapes Commander and beyond
Here's how the deck looks with the upgrades added: Also to pre-emptively address some comments: one direction that you can take the upgrades is to really lean into Sliver Gravemother's encore ability and turn the deck into a straight-up Encore deck -- Buried Alive and Entomb cards to put slivers into your graveyard, Convergence of Dominion and Zirda, the Dawnwaker to make encore cost less (though PSA Training Grounds doesn't work, I see people suggesting it but sorry no), Mondrak, Glory Dominus to double the encore tokens, Sundial of the Infinite to keep the encore tokens permanently -- that sounds sweet and all but you'd need to do a massive rework of this entire precon, turning it from a Go Wide Sliver Combat deck to Sliver Reanimator essentially
DISDAINFUL STROKE When evaluating a counterspell, the biggest consideration is how its mana cost will line up against the cards its countering
The Earth Crystal Easily the best of the Crystal cycle
Ive done this before in recent years, but given that this is the culmination of the Bolas story arc, now is the time to do it right