Maria Renard is one of the primary characters in the Castlevania: Dracula X series, consisting of Rondo of Blood and Symphony of the Night. She is a playable character in both games, and plays a central role in the stories. Maria winds up falling in love with Alucard, much as Sonia Belmont did before her in an alternate timeline. It's not known if Alucard returns her love, but there's strong hints that her romantic feelings are one sided. She is a member of the Renard Clan, and has distant blood ties to the Belmont clan. In Castlevania games, she is often quick, highly mobile, and uses animals to attack or as companions.
Castlevania: Rondo of Blood
Maria's first appearance was in Castlevania: Rondo of Blood. When her village was ransacked by the dark priest Shaft, Maria was kidnapped, along with many other young women. While in captivity, she witnessed the deaths of her parents. She was held hostage by Dracula's forces for a period of time, and met Anette, who becomes like a sister to her. The two were quickly split, as Shaft sensed great power within Maria, and wished to possess it. She is eventually rescued by the Vampire Hunter Richter Belmont, who she has heard about from Anette. Richter scares off the dark priest who had been working on the young girl. Shaft had released her power, granting her magnificent strength, and the ability to fight alongside Richter to take down Dracula.
Castlevania: Symphony of the Night
Four years after the events of Rondo of Blood, Maria is now seventeen years old. Richter Belmont has vanished, and Dracula's castle has once again materialized. Maria seems to be the only one who can get to the bottom of this, and sets out for Castlevania. There, she runs into Alucard, from whom she learns that Richter has been possessed, and the nature of the mysterious castle. After doing battle with Alucard to see who would be best to go after Richter and losing, she gives Alucard the Holy Glasses so that he might see the truth. He wears them, and sees that Richter is being possessed by the dark priest Shaft. Alucard goes off to destroy Shaft once and for all, while Maria takes Richter to safety.
Once Alucard defeats Shaft and Dracula, he takes off. Maria, however, developed feelings for him, and pursues him, insisting he stay. He decides not to return to his sleep, but avoids her as long as he can. Over a period of time, Maria tries to helps him cope with having "killed" his own father. After a brief period of Alucard's name being tarnished, Maria is injured trying to fight against the succubus Marius, and Alucard finally show some reaction towards her seeing her near death. Once she is healed, Alucard refers to humans comparing them to flowers that Maria mentioned to be "clustered and exceptionally beautiful" and that "One could crush them if one is not careful". When she decides to stay insisting that he needs her and she would try improve her cook skills to serve Alucard better, he just sighs tiredely, leaving ambiguous if her stay is welcomed or not.
Maria appears as one of the playable characters in the Castlevania fighting game Castlevania Judgment. The story sees her pulled into the time rift at some point between the events of Rondo of Blood and Symphony of the Night; she is older than her Rondo of Blood appearance, but not yet the young woman that she would become in Alucard's adventure. Like the other characters, Maria's Judgment design was created by manga artist Takeshi Obata; her design appears to have been influenced by Obata's design of the Death Note character Misa Amane.
In Judgment, Maria's weapon is a magic staff, the head of which being a cage that holds her pet owl Osca. A weak physical fighter, Maria's fighting style is based around magic spells meant to damage her opponent from a distance, including one that drops a boulder on the enemy and another that summons a large wave of water. In her Hyper Combo attack, she charges the enemy, only to trip and fall. Osca drags Maria toward the enemy before dealing severe damage.
Maria's personality and her story mode are played entirely for humor. A young teen girl, she exhibits an anime-style personality trope of breast envy, marveling at the breasts of the other female fighters. She's also at least partially oblivious to the fact that she's in a time rift, and wonders why Simon has Richter's whip when in fact the same whip belonged to both men in different eras.