Even if it ended up the same with poor Adonis dying, I liked how Guts carried out the assassination in the movie more.
Most notably was his decision in the movie to use a normal longsword instead of his signature greatsword. It was a bit more realistic to not use such an obvious weapon to kill someone in the kingdom. Hiding behind the door and ambushing Adonis was more reasonable for him accidentally killing him too. He might be great on the battlefield but he's sloppy with the clean-up jobs hahah