Luna Clear

Luna=Clear was the Saint (Holy Maiden) of Marsterria, having status and powers comparable to the Pope.

Battle Goddess Zero
Luna=Clear first introduces herself to Celica Sylphil in order to get his help to deal with Aidos. In the end, Aidos was defeated by Celica in the Palace of the Interval which was built over the gaping dimensional hole that lead to God's Graveyard, a place that robs a God of their Divine Power. Luna=Clear helped Celica escape God's Graveyard by maintaining the bridge that was the link to the outside world.

Battle Goddess Verita
300 years pass, and Luna Clear seeks Celica out once again to request his help in suppressing Beelzebub Palace. In exchange, Luna=Clear promises that the church of Marsterria would ignore the existence of the Godslayer so long as she is saint. During the raid, Luna=Clear attempts to prevent demon Nergal from taking the raid party with him in an explosion after he was defeated. The explosion was suppressed, but Luna=Clear fell through the resulting hole made in the floor along with Celica, who tried to save her. They share a kiss while trapped in the hole before they are rescued by their companions. Luna=Clear parts ways with Celica after Bezelbebub Palace is sucessfully supressed.

For a time, Celica lived at peace with the Church of Marsterria. However, after the pope of the church of Marsterria passed away, there was a shift in church politics. A new pope, Kineriusu (キネリウス) the third took his place and as his first order of business, Kineriusu transferred Luna=Clear's saint status to Luna Mea, and gave Luna 3 tasks for her to prove herself worthy of being a saint again.
 * 1) Reclaim apostle status from Sylphya Ruhans.
 * 2) Defeat the demon invasion.
 * 3) To find the Godslayer, bear his child, and then kill him.

Luna=Clear unhappily completed the first task. During the second task, Luna unexpectedly encounters Celica, and after a series of events, she, her squad, Celica, and about a hundred refugees wind up trapped in God's Graveyard.

They start a small village with the refugees, and through their time alone together on expeditions, Luna=Clear and Celica grow closer. Luna=Clear eventually gets pregnant with Celica's child. Meanwhile, 50 years passes in the real world, and Ekria with the help of Naberius and Rita Semih arrives on God's Graveyard to rescue Celica.

However, a Cardinal of Marsterria's church, Pleiades (プレイアデス枢機卿), along with Pope's personal army arrive shortly after with other plans. As Celica attempts to leave God's Graveyard, he is confronted by Luna=Clear, who fights him to prevent him from returning to Dir Lifyna.

Just as they are about to slash each other, they stop their blades. Luna=Clear confesses that she cannot kill Celica. Seeing Luna=Clear's inability to carry out her mission, Pleiades decides to kill Celica himself. However, Luna=Clear shields him with her body and is mortally wounded. She reaffirms her love for Celica as she dies in his arms, along with their unborn child within her.

Trivia

 * Luna=Clear is able to sense the breath of life. She was able to tell that Sylphya Ruhans was pregnant even though the latter told no one. This is probably how she knew that she herself was pregnant.
 * There is a clear attempt by the writers of the story to link Luna=Clear to Astraea, although it is unclear how exactly both of them are related.
 * Celia is reminded of Astraea when he is with Luna=Clear, and Luna=Clear in turn said that she feels she had known Celica long before they first met.
 * Luna=Clear loves Celia because of his peace loving and kind soul, the same reason as Astraea.
 * The fragment of Celica's past claimed that it was to Celica what Luna=Clear was to Astraea.
 * Luna=Clear's battle with Celica is similar to Astraea's final battle with Celica. Just like Astraea, she was unable to kill Celica. Celica in turn, said "I don't want to kill you a second time either." He said this from his lost memory, but the one Celica previously killed was Astraea, not Luna=Clear.
 * Luna=Clear sacrifices herself to save Celica's life, just like Astraea. Before she dies, she, like Astraea, tells Celica to "live on", to prevent her death from pushing Celica into suicidal depression.
 * Like Astraea, Luna=Clear kept a grave secret from Celica during the time they were lovers. Astraea's secret being that she was an ancient god (and thus a sworn enemy of the present gods Celica worships), and Luna=Clear's secret being that it was her mission to kill Celica.
 * Her tent in the Village of Start was called "Tent of Luna clearness" in Battle Goddess Verita.
 * It is strongly implied in the series that Roka is the reincarnation of Luna Clear.
 * Celica kept a cross shaped stone given by Luna=Clear before his last expedition in God's Graveyard. This stone was with Luna=Clear from the time she was born. It broke and saved Roka's life in La DEA of Libra.