Rukarumel on the battlefield with "Sliver" chosen.
Steps
Cast Phyrexian Walker by paying ({0} magic symbol) , and choosing to pay its replicate cost an arbitrarily large number of times by paying ({0} magic symbol) .
Phyrexian Walker triggers, creating a copy of it for each time its replicate cost was paid.
Resolve all Phyrexian Walker spells, causing the nontoken Phyrexian Walker to enter the battlefield, and creating a token copy of it for each time its replicate cost was paid.