Hello friend. Thranduil's scar - I do think it was from the war of the first age, maybe not dragon fire but definitely from that period. What else could he be referencing? Anyway the scar scene reminded me of Galadriel's scene in LOTR, you know where she demostrates to Frodo how she would become if she had the ring. In my opinion Thranduil's scar is the illusion, as opposed to his clear face.
I think the illusion theory is the best theory.
If he did have a scar, it would have had to be from the first age. Smaug seems to be the only dragon left in middle earth after the War of Wrath. It would have had to be from that war.
But yeah, it honestly did seem like an illusion, as the 'scar' was more of a fresh wound than an actual scar. He could have very well been in pain from transforming half his face into an open wound. Plus, as Beorn was transforming earlier in the movie, HE sounded in pain, even if his transformation wasn't just an illusion.
So I agree with you, friend. I also think the scar is an illusion. I don't think he was pouring his heart out to Thorin. He wants those jewels, and I believe he was trying to use shock value to sway Thorin to his side. Because when Thorin doesn't react, Thranduil reacts as if 'Well that didn't work, maybe the dungeons will change his mind' and basically dismisses him.
