Merrok

Proconsul Merrok was a Romulan male, a keen sponsor of the Tal Shiar and no friend of the Cardassians

Merrok was Enabrin Tain's arch-nemesis, he backed the Klingon-Romulan alliance and subsequent exchange of cloaking technology with the Klingons in an attempt to have the two empires 'contain' the Cardassians. Later he was a persistent thorn in the side of Cardassian/Romulan negations to exchange advanced Cardassian weaponry for cloaking technology.