Eraldo Coil is the name of the second most famous detective in the world. In reality, it is an alias that is used by L in certain types of cases. L also told the Japanese Task Force that he used the alias as a method to further conceal and hide his true identity. Aiber was allowed to pose as Coil to trick the Yotsuba Group during the Kira Investigation. However, in Death Note: Another Note, it is revealed that Eraldo Coil was an actual person before giving up his name to L.