Sir Iroas is a high-ranking knight of the Waether Empire, sent personally by Emperor Solderlight to investigate the activity of vampires on the Sphere of Garude, and the whether or not it has any connections to The Silence of Life.
Given the Bulwark Empire's refusal to interfere in the affairs of vampires on Garude, the Waether Empire deemed it necessary to look into them in relative secrecy; the power behind the vampire nobility of Garude, both magical and political, could possibly be a variable in the Silence's continued existence.