RP advice: How to turn a good-aligned PC into full vampire

[DynV]

And to continue the subject RP advice: How to turn a good-aligned PC into full vampire, by full vampire I mean a character that would react very close to what one would expect a NPC would in the same circumstance; things along the line of attacking humanoids (I guess around roads since I've seen the vast majority of those outside buildings there), and possibly luring them before.

This is my PC but just 2 levels ago, but I'm getting bored and would like to start Dawnguard soon, but would very much like to figure out how I'll RP this (in my mind) ahead. And that was his rap sheet but a few gameplay hours ago, in which the only 2 thefts were to help people in desperate situation and 6 assaults were likely all at Thalmors. I see my PC as good-aligned, which is pretty much opposed to what I'd like him to become. So far my only 2 ideas are not good at all.

Perhaps someone know of a decently-well thought-out way of making such an important alignment shift.

Thank you kindly for your consideration, and hopefully help

[MidbossVyers]

Just don't kill innocent people. Some a-hole levels a 12-gauge at you. You drain him, skin him, bash his skull in. Self-preservation is also a part of being human. My favorite part, in fact.

Actually, I can't tell you how much I despise narrow-minded people who think that vampires are only the 2 opposite extremes of emo hypocrite or bloodthirsty animal.

[DynV]

Well... It turns out I don't need to attack people. As a vampire lord, I get attacked by pretty much everyone; I wiped out almost all of the Skaals that way. I wasn't trying to pick a fight with them, I just like that form and it turns out I don't care much about mortals anymore. I'll make sure to revert form around villages, but that's it. Most of the Skaals I killed were at a All-Maker Stone, the others were outside the village.