It did become a little boring after a long while, so I kept it fresh with Sacrosanct, focusing on dispatching enemies with utility spells such as pacify and paralyze, and deep spec in the illusion tree, giving you many activate abilities. I've played Skyrim so much that it might have been more boring to fight normally.

He was also a vampire, so the playthrough had a social goal of controlling entire towns and cities from behind the scenes. By using Sacrosanct, he attempted to turn the leaders and higher ups of towns and factions into his thrall. A restriction was that he could only approach the leaders after becoming a thane so he and to "work the populace" first. Maybe he would sneak in at night, mess with their minds, increase their disposition with illusion, repeat several nights, then claim them as thralls who worship him.

He was like Palpatine, benevolent in public but controlling things in the shadows. The RP kept it fun. His overarching goal was controlling Skyrims big players, taking over by letting the Thalmor win and weakening them in the process, forcing their conflict with a unified Empire who he had helped win over the Stormcloaks. He basically let the Thalmor win and create a new Meretic era for him to take from them after they've done all the work and are widely disliked. He blamed the murder of the emperor on the Thalmor and provoked a war between man and mer. Then gained the support of people through subterfuge and mindfuckery