So I created an NPC to help my players through Death House. Brad Bradson, half orc cleric, and all around good dude. I put him in because one: I had a party of three, two of which this was their first ttrpg experience, and two: I wanted to kill him at the end of Death House.

My plan was to have Strahd kill him after the players found the shrine in the basement. Strahd realizing the party is there, goes in and kills one of them and disguises himself as them to observe.

The players make it out of Death House to find a chest in one of the other buildings around back of the house. They open the chest to find it is actually a coffin, and Brad Bradson is inside, dead. They turn around, Strahd reveals himself and applauds them on their efforts and welcomes them to Barovia and leaves.

I was hoping they would bury the body and go, but the more experienced member of the party suggested burning the corpse. When they did so, I asked them if they were torching the building or the body, they said the whole building. Cue cinematic walk away from a burning building. End of session.

My question is, can I realistically bring Brad back as a vampire spawn? Is it unrealistic to assume the body survived the fire? Or maybe Strahd came back to recover it before it was too far gone?

I think it would be great to bring Brad back as an enemy later in the game as a vampire spawn, perhaps covered with burns. The party really ended up loving him, they gave him a touching eulogy while the bard sang in the background. If he came up again as an enemy I know it would be epic and they would love/hate it, but maybe I should let this go and leave it there.