Janus of Mercere originally comes from the region where the covenant Anulus Connectens is later founded. He was discovered by a Redcap keeping tabs on offspring by members of his house, looking for Gifted children. Upon discovery Janus was brought to Harco for training after a Redcap had negotiated with his mundane mother.
During apprenticeship Janus was taught Mutantum magic as well as a broad repertoire of arts and spells useful for aiding travelers. He was discovered to possess a knack for magic regarding comfort and health in living spaces, and many of the same arts were appropriate for this as well. This aspect of his magic was encouraged and he was highly trained in labwork order to best serve his house as an enchanter and caster of supportive spells.
With these skills in mind Janus was chosen to build, manage, and constantly improve a small, strategically placed Mercer house linking two neighboring tribunals and in terrain difficult to traverse. By offering a safe and comfortable place to stay and by being able to cast long-lasting support spells for the journey on Janus hopes to become a nexus for Redcaps and other traveling magi, drawing them off their normal routes to enjoy his hospitality.
Another priority for Janus is to father many children, in the hopes of producing a Gifted heir. While his Gift bothers mundanes, those with magically aligned abilities or powers are unaffected and are even drawn to him. Whether or not this increases the odds of his success is uncertain. He plans to offer all his extended family positions at the covenant in order to better keep tabs on them.
All in all Janus' main driving goal is to ensure the legacy of his house and his own lineage.
Design is centered around the concept of creating devices for the covenant. As Major Hermetic Virtue I went for a Focus in 'Home & Hearth', to cover effects for comfort and healthy features in the Mercer house. Effects in mind are heating, cooling, clean air, ward against weather, ward against vermin, disposal of garbage and latrines, cleaning up. Not effects on the structure itself but rather on what's inside. I went with Major because of the broad scope and many Tech Form combinations.
To complement the lab applications I chose Affinity with Magic Theory, Puissant Magic Theory, Inventive Genius plus Cyclic Magic (Autumn and Winter) to optimize the general bonus. Plus the Cyclic Magic gives an excuse to be outside he lab a fair deal of the time.
Since Gentle Gift is not possible because a Major Focus already occupies the Major Hermetic slot. But in order to not get run out of town by a mob with pitchforks and torches he has not only Inoffensive to Magic beings but also Alluring to Magic Beings. Note that these virtues also affect mundanes with magically aligned virtues, flaws, and abilities.
As free house virtue I went with Mutantum Magic instead of the standard Puissant Creo or Muto, this is listed as an option in True Lineages. Not that a Puissant Technique isn't sweet all the same. Coupled with Enduring Magic there is bound to be some interesting use of this.
For Flaws he has a Major Driven personality trait; he is dedicated to his house and lineage and it is an never ending goal. Slow Caster and Weak Spontaneous Magic limits his field expertise with magic, but that's where devices and spells cast in advance come in handy. I'd like to have had the limitation of only casting spontaneous magic by ceremonial methods, but this does not exist as a separate flaw only as a drawback of Mercurian Magic. I could have invented it as a new minor flaw, but I was already drowning in them and needed something Major. I was also looking to limit Janus with Deficient Form (Imaginem) and Incompatible Arts (Pe & Mu Im) since illusions and appearance change are real useful tricks. In stead I went with Deficient Tehcnique (Intellego) to make tracking missing Redcaps challenging. For Story Flaw I went with Close Family Ties because of his ambitions of a large family. Plus Busybody specified to be about amorous liaisons among covenfolk and villagers, in order to try and track the best traits to try and bring into his family.
Most of Janus' spells are customized versions of common Hermetis spells, designed with specific parameters to take advantage of his use of metamagic and Mutantum properties.