As someone who is not yet familiar with the Divinity universe (I played Divine Divinity, but it was a long time ago - I remember that I liekd it, but not more), my thoughts as someone without knowledge aboute the world:
The trailer gave me Wicker Man/Midsommar/ generell folk horror vibes and I'm in for it. Folk horror is one of my favourite genres, so I was excited. I do think, Larian is good with darker storylines - act 2 in BG3 was my favourite, I also liked the creepiness of teh Auntie Ethel storyline and House of Hope.
I loved the music a lot, it does fit the setting as far as I can say.
The whole setting looks pretty interesting to me and teh trailer made me curious.
