Unyielding Soul is a veteran super-first-rate Guild that operates primarily in the Dark Night Empire. At it's peak, it had been stronger than many Super Guilds, however due to unknown reasons, the guild's power had diminished. Currently in God's Domain, due to their conflict with the Starline Corporation, they were being pushed out of the empire.
The guild was promoted to a 3-Star Guild due to obtaining a first clear of a large-scale Hell Mode Team Dungeon, the method of promotion is not mentioned, but it should be via a 3-Star Guild Promotion Order.
|Silent Soul||Guild Leader|
|Tier 2 Assassin||Guild Leader(former)|
|Unyielding Heart||Tier 2 Berserker||First Vice-Guild Leader|
|Mu Lingsha||Honorary Elder|
|Soul Oath||Tier 2 Guardian Knight||Upper Echelon|
|Cycling Light||Tier 2 Cleric||Core Member|
|Long Soul||Tier 2 Elementalist||Chief Elementalist|
|Hunting Blade||Guardian Knight||Chief Guardian Knight|
- Obtain the First clear of a large-scale Hell Mode Team Dungeon
Unyielding Soul was mentioned again in the story, after Zero Wing and Hundred Flowers Pavilion were able to defend Moon Creek Town from Starlink's siege of 300,000 elites and experts players and 120 Large Ballistas. The upper echelon were impressed by Zero Wing's performance and were hoping to get into an alliance with it, they were willing to offer 3% of the guild's share in exchange for 10% of Zero Wing's. 
Unyielding Soul was mentioned again, when news of the Stone Forest Town being transferred to the Bottomless Abyss was discovered. Silent Soul immediately got Unyielding Heart and Mu Lingsha to visit Zero Wing's headquarters in White River City, to negotiate on gaining a temporary Residence in the Town. He gave them full authority and was willing to offer some of their central Shops in the Dark Night Empire in exchange. 
Purchase of Twelve Elemental Pillars Magic Barrier (Chapter 2444)
It was mentioned that the guild had ordered a small number of Twelve Elemental Pillars Magic Barrier to test out but after seeing Zero Wing's display of power in Stone Forest City, revealing their 556 Level 115 Tier 3 Knights, they changed their order to huge orders instead.