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
10 set Disney Lorcana Buzz Lightyear Promo Card Tokyo Disneyland Limited Japan
Losing the game
all look correct to me A few things still make me cautious: The set number (bottom right) looks a bit thinner than Im used to seeing (does not apply for the Mewtwo card) The back of the cards looks slightly more faded/lighter than other Base Set cards I own The black traceline / outline of the Pokmon artwork seems slightly blurry compared to non-holo cards Ive attached front and back images of all four cards
Her mentor, Syr Vondam, has two cards in the set as well
If an abundance of artifact tokens and mana interests you, consider putting Roxanne, Starfall Savant at the helm of your next Commander deck