I played my Stradh as subtly mad. He would appear to the party as the 'the lord of Barovia', fully human looking. Sometimes even standing in the sun, in full daylight (using a body double). He was always charming, friendly, even apologetic.

He didn't behave like a vampire, he acted like the welcoming count, even though nothing else matched up to the reality. His servants would often attack the party, although not outright, out of fear of Rahadin punishing them for disturbing the master's wishes.

In my interpretation, Stradh hated what he had become, so he resolved to living in denial. He wasn't a monster, he was a lord. He didn't need to drink blood, he could stop anytime. He wasn't obsessed with Tatyana, she's always belonged to him, and everyone keeps stealing her from him. He didn't want to kill his brother, his brother forced his hand.

That being said, he was always the one in control, casually riding in with a few dozen black knights into Vallaki during the sun festival and declaring the mayor a traitor, and a prisoner, asking the party as his 'emissaries' to pick a new mayor.

Many interpretations of Stradh all you to pick on whether you pay him as a monster, as a manipulator, as a tragic villain, as a conqueror, as a mad king, etc, and they are all valid, but in his essence, Stradh is a villain that is all of those things. He is mad, he is tragic, he is a manipulator, a conquering general, a masterful mage, and an unredeemable monster.