You control a permanent that is boosting the toughness of all your creatures by at least 1.
You control at least one additional creature.
Steps
Activate Shilgengar's first ability by sacrificing another creature.
When the creature dies, Pitiless Plunderer triggers, creating a Treasure token.
Resolve the Shilgengar ability, creating a Blood token.
Activate the Treasure by tapping and sacrificing it, adding ({1} magic symbol) .
Activate Karn by paying ({1} magic symbol) , causing the Blood token to become an artifact creature until end of turn. The Blood token will not die due to the permanent stated in the pre-requisites causing its toughness to be 1 or greater.