El Dorado is one of the original characters in Metal Slug Attack.
He is a billionaire who lives in the Sand Kingdom. At some point he invented an armored suit powered by plasma and equipped with a high-powered jet engine; this helps him protect the sand kingdom from the rampaging Assy Nero.
He is cool and calculating, though with a somewhat sharp tongue.
El Dorado first appears in "The Sand Kingdom and the Golden Hero", where he intervenes in a fight between the Rebel and Regular Armies. He orders both sides to lay down their arms and surrender or their lives will be forfeit. The Rebel Army believes that he is a joke and fire at him, but are quickly scared off by his impressive arsenal of weapons. He then spots Eri and asks her to surrender.
Eri recognizes him as the Golden Hero and he is impressed by her research on him, and also reveals that he knows about her as the "Memphis Bomb Princess". He later reveals that his name is El Dorado and allows Eri to tell her story to him. He tells her that since the Rebel Army arrived, the town has been suffering from a lack of supplies. Eri wants to help him but he does not want any army entering the city. El Dorado tells Eri that he will march with the Regular Army throughout their time in the kingdom. Eri allows him to join, not wanting to refuse his offer.
As the Regular Army launches their offensive, Eri reminds him that the ruins will turn into a battleground, to which he replies that he is aware and is why he is coming with them. When Abul complains about how he had been waiting for them and that they are fighting like cowards, El Dorado already knows that Abul is an incompetent commander. After Abul flees, El Dorado tells Eri and Fio to go on ahead and that he will catch up later.
When Eri and Fio run into Vita, El Dorado arrives with a Slug Gunner, telling Fio that it was from his private collection. The Slug Gunner he loans helps Eri overcome Vita. After defeating her, they find Abul Abbas. El Dorado vows revenge for harming the people of the Sand Kingdom. When Eri destroys Assy Nero, El Dorado asks Eri if he can take custody of Abul. Eri allows him to do so, and El Dorado takes Abul to an unknown location.
- He is heavily based on the Marvel Universe superhero Iron Man.
- His suit is an edited version of the Slug Armor.
- When added to the same deck, he and the Professor form a team as "New Face II", lowering their AP cost by 10%.
- El Dorado is a Spanish term for "the golden one" which briefly explains why he proclaimed himself as a golden person.