Activate Phyrexian Altar by sacrificing Forsaken Miner, adding .
When Forsaken Miner dies, Sephiroth, Fabled SOLDIER // Sephiroth, One-Winged Angel triggers, targeting an opponent.
When you commit that crime, Forsaken Miner triggers, causing you to pay to return it from your graveyard to the battlefield.
Resolve the Sephiroth, Fabled SOLDIER // Sephiroth, One-Winged Angel trigger, causing target opponent to lose 1 life and gaining 1 life.
Repeat.
This sleek loop turns the humble Forsaken Miner into an endless cycle of sacrifice, feeding Phyrexian Altar for black mana while constantly draining your opponents. Every time the Miner hits the graveyard, Sephiroth, Fabled SOLDIER // Sephiroth, One-Winged Angel notices a creature dying and targets an opponent, which neatly counts as committing a crime. That criminal act triggers the Miner's own ability, letting you use the mana from the Altar to bring it right back to the battlefield ready to go again.