This is my issue both ideas appeal to me I have.
Option 1: Retiring Louis, The Overseer enters
The Overseer is a wizard though only proficient in Thaumaturge magic. His family built a complex known as the Leyline/Nexus within the city of Glasgow at the tail end of the 19th century and built a complex known as the Sentinel Works, a now abandoned location in real life, in 1903 to hide what was beneath. The Leyline/Nexus was built to regulate an unstable leyline with the family helping earth the excess energy flow however their method was dangerous as the family member filtered the energy through a device then into themselves. Many did not live beyond 30. The Overseer as he calls himself, was raised under the previous Leyline watcher his uncle from a young age as he seemed to have a talent for manipulating the energies. As his Uncle passed the Overseer was only 18 as he created small items to explore outside for him. He watched on as he saw Glasgow rotting from the chaos and he unable to leave this place due to what could occur if something went wrong on his watch. As he got older he learned how powerful he could be using the Leyline as well as his Thaumaturge leading to him searching to find agents who would do his bidding so he can save this city at any cost.
The Leyline/Nexus would act as a base for the group. It houses space for 12 people, a holding cell beneath, an Arcane Library, Arcane Workshop and Foundry. More details to come per say. This would be option 1.
Option 2 Louis continues, he loses himself to Cu Sith.
Now I can expand more on Cu Sith. In Scottish mythos Cu Sith is as described earlier a large green hound with green fur, the size of a large house with a braided tail. Now it is said he howls three times before he begins to hunt down a soul dragging them away or abducting young women for fae children to feed on. Sort of a Scottish Grim Reaper. Basically in our world he follows this but is one of many hounds that serve the Erlking so he isn't uber powerful but holds significant power. Louis as each time he loses control he succumbs to the hunt and Cu Sith being able to manipulate him more. After a recent White Court stand off he meets with Cu Sith to learn of his next assignment which is to act as a neutral party at the upcoming court deal however Cu Sith asks Louis what was the last noise he heard on the night of his parents death. The answer is 3 howls. Turns out Cu Sith or one of his relatives was hunting down his mother but since she and his father fought them off they were killed for such defiance and Louis left to rot. At this point Louis loses his mind as he draws his weapon on Cu Sith but it warps forming two leather "bracers". Cu Sith's eyes glow as Louis is forced into the shape of a large hound with green fur and a braided tail. Cu Sith informs him he is now his toy and that he never killed Louis' parents but he needed him to snap to be more effective. He is now a true hunter and will keep hunting as long as he is needed as a dog. Louis is now bound as a Hellhound but his will allows him retain his sense of self and despite acting as an agent he plans his next step to found out which of Cu Sith's kin or even Cu Sith himself killed his parents so he can take the revenge he has wanted and as a new head of the pact protect humanity.
Option 3: Uh...any evil ideas you guys have
So yeah what do you think....I have such mixed feelings overall.