Please help me decide on a Paladin Build for Curse of Strahd

[Yunru]

You don't have to lie to mislead, plus there's always the greater good:
Fighting the prime evil saves more kittens than saving kittens from trees.

 

[UngeheuerLich]

I don't insist on anything I just think that Paladin levels 7-10 and higher are far less good than 4 levels in Sorcerer. When to take those levels is of course very much the question.

As for the Oath. I can see the benefit of Devotion. The Problem is the Tenets. I am not Lawful Good, but Chaotic Good. So i'd be really toeing the line there. Chaotic Characters usually don't "obey those who have just authority over you" (although "just" sounds like its a wide open loophole) and also Deception +7 is kinda a no go if i can't lie And frankly this whole over-the-top goody-two-shoes thing sounds like a real drag. Like I can't fight the prime evil because i was so caught up in getting kittens out of trees and now i have to pay reparations to the whole world because it was somehow my fault that all these bad things happened. That doesn't really inspire me.

The immunity to being charmed may prove useful... but if you rather go avenger, sorcerer seems a good way to branch out. Advantage on an attack makes losing your second attack a little less hurtful. Warlock celestial patron might be quite interesting instead of divine soul sorcerer. They also get bonus damage on fire and radiant attack at level 6. You won´t be able to quicken a spell (but you can just double smite by using searing smite and a divine smite together.
The nice thing: searing smite deals extra fire damage each turn, greenflame blade does so too. So you double down on that extra fire damage. I think using smite and divine smite is less resource consuming than quicken spell. I also like the idea of having invocations. Depending on the pact there are a few nice ones. Book of ancient secrets. Or maybe even aspect of the moon. Gift of the ever living ones.
Or beguiling influence if you really like deception. If you miss a second attack once in a while, thirsting blade helps. improved pact weapon too. I think the warlock path is stronger than the sorcerer one.

 

[Seramus]

Hexblade 1 / Paladin 9.

Raven Queen is perfect for this. She is a neutral entity who empowers people to destroy undead, which is exactly what you are doing in Curse of Strahd. Paladin is who you are, Hexblade is the job you have been given. Set forth to destroy a vampire who has tormented the land and eluded her grasp for centuries.

I went Paladin 9 to get Aura of Protection early and access to 3rd Level spells. A second level of Hexblade is always an option.