Ok, so to aid in breaking the tie and getting a workable result, here's a breakdown of the current leading options.
Artistry will make you renowned for your mastery of poetry, song, dance, storytelling, painting or any other form of art. Please note that while your Creator knacks apply just as much to works of sculpture and painting as blacksmithing, this purview will not directly benefit your engineering in any way, outside of helping to make your creations more aesthetically pleasing. However, it should be remembered that you are a lowborn Engineer who only recently graduated - you will need a patron or some other form of "in" to get the wealth and material resources necessary for large projects, or to get invitations to prestigious events. Being an excellent artist as well as a capable Engineer will make that kind of undertaking much more useful, and will steer the quest in that direction.
Epic Dexterity is the only one of Myrmidia's purviews which directly enhances your physical capabilities and ability in combat. Other purviews can conjure up blasts of divine energy or reshape the battlefield, and War buffs your knowledge and allies, but Epic Dexterity gives you the speed and grace to personally cross swords with hostile champions or extricate yourself from danger (though you'd want actual martial training to make the most of it). It benefits both melee and ranged combat (one potential Boon is the ability to ignore all environmental penalties to your accuracy and extend your range to line of sight), but the civilian applications are more limited, largely in the form of just being very graceful and elegant.
Sun works with both the literal elements of the sun (blinding light, blasts of holy energy) but also governs more emotional or abstract associations such as hope or rebirth. Boons include directly stirring the hearts of others to cure fear, depression or malaise, or tearing through disguise and illusions with the light of truth. It is also the most overtly supernatural of the three leading purviews, which might be a good or bad thing depending on your preferences - people will very swiftly cotton on to the fact that you are divinely empowered when you start working miracles of this purview. Sun will tilt Valeria towards being a figure of inspiration and hope, someone who leans into her legendary title and Judge calling to drag the sins of the night out into the daylight.