Knull Gravefather

The “Legend rule” doesn’t apply to Slivers you control.

Each Slivers creature 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.)