Tactus, from Ultima V: Lazarus
The Avatar found Tactus busy in the Darkwatch Armoury, believing his armour to be the best in the land. Talking longer to him, he revealed that he felt that Blackthorn was a great guy, who he felt was exactly what Britannia needed. If the Avatar chose the careful path and pretended to agree, Tactus revealed that he knew Judge Dryden, suggesting the hero ask him about the Oppression and mention Tactus' name to the judge.
With this information, the Avatar managed to find a way into the Oppression.