You control lands that produce at least ({2} magic symbol) ({W} magic symbol) .
({1} magic symbol) ({W} magic symbol) available.
Steps
Activate Altar of Dementia by sacrificing Peregrine Drake.
Sigil of the New Dawn and Deathrender trigger.
Resolve Sigil of the New Dawn's trigger, paying ({1} magic symbol) ({W} magic symbol) to return Peregrine Drake from your graveyard to your hand.
Resolve Deathrender's trigger, putting Peregrine Drake from your hand onto the battlefield and attaching Deathrender to it.
Peregrine Drake enters the battlefield, triggering itself, untapping up to five lands you control that can produce at least ({2} magic symbol) ({W} magic symbol) .
Resolve the Altar of Dementia ability from step 1, causing target player to mill four cards.