Due to grey morality of Dragon Age series and questionable goals Pyral Harrowmont can be considered as a villain especially considering his actions if he becomes king.
Lord Pyral Harrowmont is the High-General of Orzammar, a deshyr in the Assembly, and King Endrin Aeducan's second. A traditionalist, he is well known for being an able administrator and has authored many compromises in the ever-warring Assembly.
Paragon of her kind
Harrowmont is one of the two candidates for the throne of Orzammar, the other being Prince Bhelen. The Warden must choose to support one of these candidates during A Paragon of Her Kind.
If the Warden says they will support him, the first task he gives the Warden is A Lord's Trust: The First Task, in which the Warden must fight in the Provings. After this, he asks for Jarvia to be eliminated. This can be done by completing Entering Jarvia's Hideout.
After that he tasks the Warden with finding Branka or what is left of her in order to assure his ascension to the throne, giving the Warden maps to Caridin's Cross in order to help the Warden in the search.
If the Warden joins forces with Bhelen, when he ascends to the throne, he will order Harrowmont executed. It can later be heard from criers, "News of the hour: Lord Harrowmont arrested, pending execution."
If you choose to support Harrowmont, you will discover later in the epilogue that his reign was troubled. By sticking to the traditional dwarven ways, he further restricts rights from the lower castes while favoring the nobility, as well as further isolating Orzammar from the surface by restricting trade and refusing outside military assistance beyond equipment and herbal aid against the Darkspawn in the Deep Roads. In the following series of rebellions, it is revealed that Harrowmont falls ill, most likely due to poisoning, and dies. If you choose to support Harrowmont and sided with Branka he uses the golems to put down Bhelen's rebellion and lives. After several riots in Dust Town, he uses the golems to practically reduce the district to rubble. Branka states that more "volunteers" are needed in order to create more golems. Harrowmont refuses, however, and Branka begins raiding the surface to capture unwilling humans and elves. This leads to a short war with Ferelden, forcing Orzammar to close its gates to the surface, thus isolating the dwarves more than ever.