Activate Phyrexian Altar by sacrificing another creature.
When the creature dies, Bishop of Wings' second ability triggers, creating a 1/1 Spirit creature token.
When the Spirit token enters the battlefield as an Angel due to Leyline of Transformation, Bishop of Wings' first ability triggers, causing you to gain 4 life.
Resolve the Phyrexian Altar ability.
Repeat.
This clever loop transforms your battlefield into an engine of endless life and mana by reshaping the very nature of your creatures with Leyline of Transformation, ensuring every token you create enters as an Angel. That typing is crucial because it allows the Spirit tokens you generate to immediately satisfy Bishop of Wings' entry trigger for 4 life and its death trigger whenever you feed a creature to Phyrexian Altar. By sacrificing the newly minted Angel token to the Altar for mana, Bishop of Wings replaces it with a fresh Spirit that the Leyline upgrades right back into an Angel, fueling a continuous cycle of sacrifices and triggers.