The Heavenly Tool Alliance is different from other forces; it exists not only in the Heavenly Demon City but also has various branches in the Eastern Continent, the other Three Continents, and the Central Region. If these branches were to unite, they would undoubtedly be stronger than the Undying Heavenly Demon Clan.
Moreover, the Heavenly Tool Alliance is an alliance of alchemists and artifact refiners. Although they only recruit alchemists and artifact refiners from the Demon Clan, they do not refuse commissions from other forces for alchemy and artifact refining. If they were to severely offend the Heavenly Tool Alliance, it would not be a good thing for the Undying Heavenly Demon Clan!
