I continue on my adventure and head to the place where Withers lives, clearing out that area, and after a few fights realize I need to long rest. We set up camp there and to my surprise Alfira comes to talk with me wanting to join us. I agree to this and finally hit the bedroll.

My character wakes up in the middle of the night to a violently dead Alfira and blood all over me. Clearly my dark urge did something that I couldn't control. I cleaned everything up and went back to sleep.

Upon awakening my party sees the horror of the bloody tiefling corpse and I told them I didn't know what happened but think it could have been me, hoping for some sort of understanding from my party members. While they were startled but willing to work with me to help figure out what is wrong with me, the Oathbreaker Knight wasn't having any of it and immediately puts us in combat with him.

He is a level 12 Paladin with all 3 auras of each subclass of paladin on him with about 230 hitpoints. Now there's no way my party can kill him. I can't even hit him. So my options are 1) go back to a much earlier save and have another character try to interact with Alfira or just ignore her completely 2) respec my whole character, making it another class or 3) reroll from the begining and don't choose the Dark Urge character.

I am in a co-op game and thinking the Dark Urge is likely to give us further problems down the road and I was looking forward to this character being a Bardadin for reasons, hence my interaction with Alfira in the first place. We ultimately chose to reroll the same classes, leaving the Dark Urge out for a solo run later down the line, as we had been planning this campaign for a bit and don't want to encounter further surprises that might stop us in our tracks like this one.