Activate Kiki-Jiki by tapping it, creating a token copy of Lumbering Battlement.
When the Lumbering Battlement token enters the battlefield, it triggers, exiling Kiki-Jiki until Lumbering Battlement leaves the battlefield.
Activate Shilgengar by sacrificing the Lumbering Battlement token.
When the Lumbering Battlement token dies, Kiki-Jiki is returned from exile to the battlefield.
Resolve the Shilgengar ability.
Repeat.
This fascinating loop relies on Kiki-Jiki, Mirror Breaker continually cloning Lumbering Battlement, whose entry trigger neatly tucks away Kiki-Jiki for safekeeping. By feeding that very same Lumbering Battlement token to Shilgengar, Sire of Famine, you instantly pop it out of play to release Kiki-Jiki from exile while also stockpiling valuable Blood tokens. Rinse and repeat this rhythmic cycle to generate an endless cascade of triggers, artifacts, and sacrifices.