The alternate(and original ending) to the film was much better imo. It was much more along the lines of the book in which Nevile realises he has become the monster. Its the same up to the point where the Alpha male starts smashing his head on the glass, then he stops and in the blood splatter draws a butterfly, which Nevile realises is the same as the tattoo on the test subject he has 'cured', and comes to realise they are attacking to try and get her back as she is the Alphas mate(and i mean that as in partner, not friend) he then also looks at all the pictures of the numerous other 'monsters' he has killed trying to cure them and comes to the realisation that he has become the monster, they are trying to get on with there lives(in there own way) and he keeps taking them away to experiment on them and kill them, becoming a legend amongst them(hence the title), culminating in him taking the Alphas partner. He then lets the Alpha male take her and the two share a close moment of reunion together and then they all leave under order from the Alpha(not to attack Nevile). Nevile then rather crestfallen leaves with the girl.
Books may still be better, but i think the film would have been much better sticking with that ending, but they went with the other one as test audiences thought it was too much of a sad ending, portraying Nevile as the ultimate 'antagonist'
