Blue Impact

Blue Impact is a guild in Elder Tale.

Overview
Blue Impact is one of the PK guilds that gained notoriety around Akihabara after the Apocalypse. They ambush and PK players around Akihabara in order to loot the items and gold they drop after their deaths.

Log Horizon: People of the West Wind
In the spin-off, Blue Impact, Canossa, and Tidal Clan are incited by Magus into PKing. For that, however, they are targeted by Soujiro Seta and Isaac and PKKed outside of the city after being lured by the members of the West Wind Brigade.