This is an origin of Prince Trevor who became Rexdian a.k.a. Masked Lion
Prince Trevor of the Stars was born on a water based planet called Aquos. He was raised up by Roy and Lisa (Trevor's parents) and they taught Trevor the way to uphold the Royal Star Lineage and was deteremind to become the next ruler of the Star Kingdom when his is older,but something went horribly wrong. One day,the entire Star Family was celebrating Trevor's 2nd birthday on a floating castle with his mother and father and all of the star kingdom citizens and was the best time of his life. Until there was a dark storm swarms over his kingdom. Then,a dark portal was summoned,and there was Queen Beryl of Negaforce,along w/Jediate,Nephalite,Zoicite,and Malacite. They came and destroyed Trevor's entire family/race,and he was in his mother's arms,but Beryl saw Trevor of what he can be,so he took Trevor out of her dying arms and took him away. (That's how he has relations w/Queen Beryl). He was tortured a lot,very painfully and it lasted for 5 years. Later on,his name has been changed to Rexdian,he is 7 years old and is training hard to become the best Negaverse Warrior ever.He even got his first kill age 7 and executed a Sailor Scout spy. He still remains loyal to Beryl,and he also became friends w/Zoicite & Malicite. Rexidan goes out on missions to take people's energy,killing Sailor Scouts and making his powers even more powerful. The reason why is that,Queen Beryl wanted to make a perfect super warrior for her Negaverse army and Rexdian is that person who will be that super solider. 7 years later,Rexdian is 14,and he became the youngest to become a General in the Negaverse army.He his happy for Zoicite & Malicite being together,and Malicite now trusts Rexdian. After reaching the rank of "General" he was sent down to the Moon Kingdom for that one mission that will change his life forever: Kill Prince Darien for betraying the earth. So once he is on the Moon Kingdom he found Prince Darien,but he is w/a girl named Princess Serena and Rexdian saw the love between those 2 and he refused to do it. Once Rexdian returns to Beryl,he told Beryl,"Mother,Darien is not a traitor,you wanted me to do this,because you are jeleous of Princess Serena and will not do this mission because of that." Once Beryl heard everything,she draw her sword and attack Rexdian. Beryl said,"Since you disobeyed my orders,I will dispose for you traitor!!!" Then Rexdian and Beryl fought each other,but Beryl won striking Rexdian in the heart. Rexdian falls to the floor and the last thing Beryl said to Rexdian is,"This is what happens when someone like you betray me,goodbye my son."
After Beryl killed Rexdain,she took his powers and sent him to a death jail cell. Where he would spend the rest of eterenity in death,all chain up. Then when Sailor Moon defeated Queen Beryl,his hold on him in death was released and he was in present-day Tokyo,Japan. Even though,his hold on him was free,it did had an effect on him,not only it gave him his dark & evil looking skin,it also caused his body to age into his earlier adult form(in which he is the same age as Darien). But he has no memory of when he use to work for Queen Beryl,the only memory he has is his own name. Also Rexdian has flashback memories of when the Sailor Moon,Tuxedo Mask and the sailor scouts fought Queen Beryl and her forces,but he knew those memories are not his and has to find out who he really is. The only clue he has is a star locket that Sailor Moon have,but his locket looked old,cracked and broken,but it still played music,but the crescent moon change colors. As he is trying to find his answers,he was suddenly attack by an evil monster,also Rexdian's left arm started to glow with dark power but it's causing him pain. As the monster was about to attack,Rexdain was saved by a white rose,and the man who threw it was the Moonlight Knight. The Moonlight Knight easily cut down the monster and as the Moonlight Knight was about to leave,Rexdian grabbed his arm and begged him to help train Rexdian. The Moonlight Knight accepted Rexdian's offer and train Rexdian on how to become a warrior and a masked hero. Before the "Doom Tree events" was over,the Moonlight Knight was fading away. So the Moonlight Knight told Rexdian he has completed his training and gave him an outfit that fit best for him. Rexdian understood of he has to do,put on the outfit,along the mask and Masked Lion was born.
Now he fights for Redemption because he was killing Sailor Scouts while he was working with Beryl and he feels the pain of regret for killing those Scouts. I'm sorry to bring this up everybody,but he did it....and he's going to redeem himself for what he did in the past.
There you go people,that is how Masked Lion was born and Rexdian got relations w/Queen Beryl.