Mercer was a relatively handsome man with hair the color of straw and a strong chin. Although he was not overly large he was well developed and was called a lady's man for his time. He wore his beard long. In battle he wore green armor with black yellow linings.
Mercer was a peer to Wilhelm Albrecht and later his chief rival.
At a young age he learned to despise the Albrechts for how low they made House Willow fall after the Blackwood Uprising, and vowed to make them pay for the offense. When Wilhelm came to power, the viscount's gluttonous spending and cultural reforms were the perfect premise for him to stage his protests against, and before long he had convinced several other houses to back him.
Mercer's rebellion inevitably led to the fall of House Willow. After the Albrechts prevailed he was stripped of all lands and titles. The Willows were replaced with House Thorne, headed by Burkhard Meadows.