Mayfil, nicknamed the Death City, is a Limbo to which souls travel when they die, and from which not all souls can leave. Its spectral residents will attack the living on sight.
Mayfil is the former Wingly city of the dead. After its total destruction during the Dragon Campaign, the souls of people and creatures that did not completely die came here. During Wingly rule, Winglies' souls were sent to the "Death City" when they died.
This is also where one of the spheres that protect the moon were hidden, and would be the last one to be unsealed.