The "legend rule" doesn't apply to Slivers you control.
Each Sliver creature card in your graveyard has encore , where X is its mana value.
Encore (, 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.)
not legal Legacy
not legal Vintage
not legal Modern
not legal Standard
not legal Pioneer
not legal Pauper
not legal Historic
not legal Commander
This print of Sliver Gravemother is not tournament legal.