You control up to seven lands that can tap to produce at least ({4} magic symbol) .
Steps
Activate up to seven lands you control by tapping them, adding at least ({4} magic symbol) .
Activate Phyrexian Altar twice by sacrificing Archaeomancer and Great Whale, adding ({B} magic symbol) ({B} magic symbol) .
Cast Living Death by paying ({3} magic symbol) ({B} magic symbol) ({B} magic symbol) , causing each player to exile all creature cards from their graveyard, sacrifice all creatures they control, then return all cards exiled this way to the battlefield.
Archaeomancer and Great Whale enter the battlefield, triggering their abilities.
Resolve the Archaeomancer trigger, returning Living Death from your graveyard to your hand.
Resolve the Great Whale trigger, untapping up to seven lands you control.