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
being an extremely repetitive "one-card combo deck" is problematic
Possibly devastating, possibly a complete dud
You then choose an opponent at random
If your deck is nothing but permanents, casting it means your entire library hits the battlefield at once
This arguably makes them the rarest cards ever and when one of them appeared at Heritage Auctions, a collector could not help but purchase it for $360,000
