Sliver Gravemother Fallout Whenever another legendary permanent you

Whenever another legendary permanent you control enters

A Traditional Foil Land replaces the basic land in 20% of Set Boosters and a Foil-Stamped Signature Art Card replaces the Art Card in 10% of Set Boosters

and it has '{2}{U}{U}: Return Sakashima the Impostor to its owner's hand at the beginning of the next end step

The embalm cost is equal to its mana cost

Sliver Gravemother Fallout Whenever another legendary permanent youThe 'legend rule' doesn't apply to Slivers you control. Each Sliver creature card in your graveyard has encore {X}, where X is its mana value. Encore {5} ({5}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)