You control at least four creatures with defender.
Steps
1Activate Phyrexian Altar by sacrificing Wingmantle Chaplain, adding .
2Wingmantle Chaplain dies, triggering Nim Deathmantle, causing you to pay to return Wingmantle Chaplain from your graveyard to the battlefield, and attach Nim Deathmantle to it.
3When Wingmantle Chaplain enters the battlefield, its first ability triggers, creating at least four 1/1 Bird creature tokens.
4Activate Phyrexian Altar three times by sacrificing three Birds, adding .