To make a bunch of money and kill a bunch of monsters.
Their guild hall is large and built in the style of a hunting lodge, with various monster parts mounted on the walls as trophies. There is also a in-house bar and dining area for Singers to take their ease when looking for contracts or waiting for new ones.
It's a loose guild with one leader and everyone else organizing themselves into teams based on the contracts they decide to take. There are a few teams which are common enough to earn their own names, but most are fluid in their partnerships. Adhi also sometimes assigns teams for missions if he believes their particular skill sets are suited to the mission, usually a particularly sensitive one.
The guild was founded two years ago when Adhi left his previous and very lucrative profession to go out on his own and do something different. They quickly became a powerhouse in the Hunter's guild world, partially aided by Adhi's mysteriously acquired wealth, and partly aided by his charismatic approach to recruitment.
Partnership, begrudging acceptance
The Triumvirate does not particularly like having to rely on guilds such as these, but if they have to, they rely on the best, and the Singers are the best in the city right now. The Singers see the government as a waste of time and would much rather have Adhi run the show, which he laughs about to no end.