Activate Viscera Seer by sacrificing Phyrexian Walker.
When Phyrexian Walker dies, Mortuary and Remembrance trigger.
Resolve the Mortuary trigger, putting Phyrexian Walker from your graveyard on top of your library.
Resolve the Remembrance trigger, searching your library for Phyrexian Walker and putting it into your hand.
Resolve the Viscera Seer ability, causing you to scry 1.
Cast Phyrexian Walker by paying 0.
Repeat.
This clever loop relies on the zero-mana cost of Phyrexian Walker to create a self-sustaining engine of sacrifice and recovery. When you use Viscera Seer to sacrifice the Walker, Mortuary ensures the card goes straight back to the top of your library while Remembrance simultaneously lets you tutor another copy directly into your hand. Because Phyrexian Walker costs absolutely nothing to recast, you can continuously replay and sacrifice it, yielding an endless stream of death triggers, enters-the-battlefield events, and infinite scry filtrations.