The Phyrexian minds that constructed it did not live past its awakening.

Phyrexian Soulgorger

Cumulative upkeep—Sacrifice a creature. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

The List

Coldsnap

Cumulative upkeep—
Sacrifice a creature. (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)

When Phyrexian Soulgorger’s cumulative upkeep ability resolves, you must either sacrifice a different creature for each age counter on Phyrexian Soulgorger or sacrifice it. You may also sacrifice it as part of its own upkeep payment.