Dr. Luis Serra Navarro was a biologist/scientific researcher who was born and raised in an unknown part of Spain which was to become the home of the
Los Illuminados cult. For a time he left his homeland in order to learn the necessary skills for his interests and eventually a degree as a Biologist.
In the original
Resident Evil 4, his name is localised as Luis Sera. In the
Resident Evil 4 Remake, he is named Luis Serra Navarro.
He returned home to find that everybody worshipping the
Plaga, a parasite which could affect humans and animals in various ways. He also developed a machine which could remove a
Plaga from it's host without killing them, as well as pills that can stunt the growth of an immature
Plaga.
He subsequently joined the cult in order to research the
Plaga parasites and use his skills to mutate them in various ways - leading to the creation of such creatures as
El Gigante,
Regenerador,
Novistador and others. However, Sera was becoming more and more afraid of what he had helped create and eventually tried to contact one of his old friends - but his friend was dead and instead made contact with
Ada Wong, then part of The Organization which was an Umbrella rival. Ada would be sent by The Organization in order to make contact with Serra and obtain a Dominant
Plaga egg sample.
Unfortunately, Serra was found out and
Bitores Mendez was sent to capture and disable him. He was subsequently bound and thrown into a wardrobe to be interrogated later around the whereabouts of the Dominant
Plaga egg sample. He encountered
Leon S. Kennedy and falsely introduced himself as a police officer from Madrid investigating the area, in order to hide his true identity. Sera was fully aware of the rescue operation
Leon was involved in at the time and thought better to be safe than sorry.
Leon, Serra and
Ashley Graham made their way through the area, pulling the
Los Illuminados apart piece by piece, but their leader
Osmund Saddler eventually had the last laugh and killed Sera by impaling him through the chest with his
Plaga tentacle.
In the Cabin part of the game where you first meet him as
Leon, Serra is an active combatant and can shoot at enemies as well as dish out items such as ammo or health items. He cannot be killed, but he will kill
Leon if he is damaged enough times by the player.
Interestingly, Serra's appearance went through a small change as the game was about to be released - he originally sported a moustache, and this can be seen in the game if you obtain his Bottle Cap.
In
Resident Evil 4 Remake, Luis is killed by
Jack Krauser instead of
Osmund Saddler. He also cannot be fired upon by
Leon (most likely an intentional choice by developers to prevent a pointless game over screen). His misogynistic characteristics were also vastly reduced (he no longer comments on Ashley).
