Requires

Steps

1. Declare Yore-Tiller Nephilim as an attacker.
2. Yore-Tiller Nephilim triggers, returning Port Razer from your graveyard onto the battlefield tapped and attacking.
3. Deal combat damage with Port Razer and Yore-Tiller Nephilim.
4. Port Razer triggers, untapping each creature you control and causing you to get an additional combat phase after this one.
5. Activate Phyrexian Altar by sacrificing Port Razer, adding one mana of any color.
6. Repeat each combat phase.

Results