Valerie Henry, who played Rinoa, was actually hit in the face by Vincent van Ommen during their action scene, as she didn't dodge the hit on time. The next day, Vincent himself received a blow on the head during the second fight of The Twins against Vann.
Davide Durbano, who played Hansel, also played other 'extras' during the bohemian party. It is actually Davide who is sitting next to Ant at the bohemian scene but his face is blocked by 'Glass'.
The first three days of shooting were lost due to a 35mm adapter that wasn't working, meaning all the footage was out of focus.
The part of Ant was originally to be played by a number of other actors, before being taken by director Pedro Chaves.
The swords used in the final scene are real swords.