Capcom's Resident Evil introduced a new type of horror game. The game was campy and hilarious, but still terrifying. And it brought with it a number of fascinating and enduring characters, Leon S. Kennedy being the most memorable. But the host of supporting characters and villains make RE4 stand out among its contemporaries.

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Dr. Luis Sera was a scientist who worked with a cult worshipping a parasite that took over the villagers in his home. After developing a conscience, he tries to escape and is found by Leon in a cabinet. He later helps him in his mission before finally dying in an effort to get Leon and Ashley the egg vaccine. His impact on the game is not limited to his short appearance though.

10 He's Not Actually A Doctor

While everyone, including himself, calls Luis a doctor, he's not technically one. He was working on his doctoral thesis when his letters to his grandfather's started coming back in the mail.

When he came back to check, he got involved with Los Illuminados before he could complete his doctoral thesis. However, he reasons that he's learned everything he had to learn to get his doctorate and is, for all intents and purposes, a doctor.

9 Leon Never Gets His Name Quite Right

Leon always pronounces Luis' name as Lewis, in the American way. Luis, however, is Spanish, and his name is supposed to be pronounced as Loo-eez. He tries to correct Leon subtly a few times but his attempts fall on deaf years, as the American soldier insists on calling him Lewis throughout the game. He doesn't get it right ever. At all. Not even once.

8 He Can & Will Kill You

While Luis presents himself as a harmless, almost foolish playboy, he's a smart and capable man. In the missions where he's accompanying Leon, he can even kill him.

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If you damage him one too many times, he will stand up, say, "Adios, Leon" and shoot players right into a game over screen. Which makes using grenades around him very dangerous.

7 He Doesn't Get Much Screen Time

For a character of such importance, Luis really doesn't get much screen time. His appearance in cutscenes runs for a total of only seven minutes.

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His presence in the game is mostly through his research notes that you find lying around. He has other contributions to the plot, however, and his research plays a key role in getting the eggs out of Leon & Ashley.

6 He Is A Commitment-phobe

Luis presents himself as a playboy, and that's not entirely a front. He is a notorious commitment-phobe. Luis brags about his partying and nightlife while in college and describes his ideal partner as any woman. The lazy foolish playboy persona works to hide his intelligence and while he uses it to distance himself from his work on Plagas, it is rooted in some truth. He also admits that he will be "the worst significant other the world will ever know." Self-Awareness is not a trait that's seen in many playboy characters.

5 He's Working With Wesker

Like most characters in the series, Sera is also working with Albert Wesker through Ada Wong. Wong convinces Sera to retrieve the Sample for the plague. In return, Wong promises to get rid of Saddler and Los Illuminados. Wong considers him particularly suitable for this because of his work in the Los Illuminados lab. He also knows a number of secret passages throughout the Village, from his time as a child exploring with his grandfather.

4 He's Responsible For A Lot Of Things You Kill

Sera's research in the Los Illuminados labs was specifically to make those infected by Plagas harder to kill. This resulted in some mutated mobs that players will find, including El Gigante and Regenerador. His research was also used to develop other human-animal hybrids. The Verdugo and the Novistador were creations based on his research, as well as the horrifying U-3 boss.

3 He Has A Fear Of Tentacles

Dr. Sera expresses nervousness and fear around tentacles multiple times. He probably was around a lot of tentacles while working with the Plagas virus.

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It makes his death pretty ironic though. Saddler ends up impaling him with his pointy tentacle appendages when he returns to Ashley and Leon with the plagas suppression drugs & the sample. Guess that's one fear of his that wasn't entirely unfounded.

2 He Loves His Grandfather

An unmentioned undercurrent to Luis' story is his love for his grandfather. His favorite food is paella made by his Abuelo. More than that though, his motivation throughout the plot is his grandfather. He learns of the virus when he finds out about his grandfather's death. When he joins Los Illuminados, it is because he is determined to find a cure for the virus that killed his grandfather.

1 He Was Supposed To Have A Mustache

Luis Sera's original character model was designed with a mustache, but he was ultimately clean shaven for the final game. However, the trial version of the game still featured him with the mustache. The Bottle Cap modeled after him also shows him in all his marvelous mustachioed glory.

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