You control up to five lands that can tap to produce at least ({3} magic symbol) .
Steps
Activate up to five lands by tapping them, adding at least ({3} magic symbol) .
Activate Phyrexian Altar by sacrificing Peregrine Drake, adding one mana of any color.
When Peregrine Drake dies, Nim Deathmantle triggers, returning Peregrine Drake from your graveyard to the battlefield, and attaching Nim Deathmantle to it.
When Peregrine Drake enters the battlefield, it triggers, untapping up to five lands.
Repeat.
If the lands can tap to produce at least ({4} magic symbol) , this combo nets infinite mana.