What movie is this ? old fantasy film with children

Okay so I’ve been looking for this film for years after watching it as a child.
I can’t remember the whole plot but I think it’s an adventure film, the scenes I remember include:
An old man pricks himself on something hallucinogenic, he then sees pixies on him. He stabs one on his chest and dies, one of the main characters (The boy) feels guilty for this.
The ending where the girl jumps in front of a bullet for the boy and dies, I think she’s wearing white and says something like ‘I’ll see you there, you’ll just be late’ or something like that.

I know it might not be much but please help! This is driving me crazy!

Thank you! 🙂