Activate Viscera Seer by sacrificing Boonweaver Giant
When Boonweaver Giant dies, Changing Loyalty triggers, returning Boonweaver Giant from your graveyard to the battlefield
When Boonweaver Giant enters, it triggers, returning Changing Loyalty from your graveyard to the battlefield attached to Boonweaver Giant.
Resolve the Viscera Seer ability from step 1.
Repeat.
This elegant loop relies on the recursive synergy between Boonweaver Giant and Changing Loyalty to constantly recycle resources right under the watchful eye of Viscera Seer. When you sacrifice the Giant to Viscera Seer, Changing Loyalty's triggered ability steps in to pull the creature straight back from the graveyard. That return immediately triggers Boonweaver Giant's entering-the-battlefield ability, allowing you to fetch Changing Loyalty right back out of the graveyard and reattach it to the Giant, priming the whole engine to fire again.