Meet the Gang.  If you're familiar with Slayers already, including a few of the whackos that show up in Slayers Next and Slayers Special, none of this will be new to you.  Otherwise, it should tell you basically everything you need to know to get familiar with the whole zany tribe, and some of the essential background used in Reflect.
Meet Lina Inverse.  Bandit killer, black sorceress, robs from the rich and gives to herself, fan of really big dinners.  Lina's been questing for a long time now, randomly slaughtering the wicked and enjoying nice soft beds at inns and sometimes saving the world.  Life on the road's made her independent (unless she doesn't want to be), carefree, and just a liiitle bit irresponsible and immature... most of her magic is incredibly destructive, notably the infamous Dragon Slave tac-nuke sized spell.
Gourry Gabriev, travelling companion of Lina's.  He's not real bright.  He's rather dense.  He tends not to quite get what's going on at any given point in time.  But he's heroic without being overly dashing, friendly without being overly crushing, and generally an all around nice guy you wouldn't mind taking home to your mother.  He also has the legendary Sword of Light, copyright Lucasfilm Ltd.
Zelgadis, part human, part golem, part chimeria, part whatever.  Softly spoken and usually the straight man to Lina's antics, he has one overall goal in life: find a cure for his condition.  He usually only hangs out with the gang when their goals match his in some way, but he knows right from wrong and will go an extra yard to protect others if need be.  He's talented with a blade and with shamanistic magic (astral planes and nature forces).
Amelia Wil Tesla Sailoon, self-proclaimed princess of love and justice, righting wrongs and dramatically defeating evil. Well, she would if she wasn't just a wee bit clumsy and incompetent... Amelia's idealistic to the point of ignorance of what could go wrong in her actions to bring justice to the world.  Her cuteness level can spontaneously cause cavities.  Fortunately, a pure heart and amazingly coincidental magical accident are sometimes just what's needed.  Has trained in Shamanism under Zel.
Naga the White Serpent, Lina's self-proclaimed archrival and occasional travelling companion split ways with her before Gourry arrived.  However, in her days with Lina, she proved to be... unique.  Sporting a very, ahem, interesting sorceress's costume, a very frightening laugh and a complete lack of common sense, Naga's skills don't quite live up to her ego.  She also enjoys teasing Lina about her figure, and usually a fireball to the face in reply.
Prince of Sailoon and father of Amelia, Philoniel ("Phil") is just as idealistic and dramatic as his daughter.  If not moreso.  If that were possible.  He's supposedly a pacifist, if having attacks named 'Goodwill Towards Men Crush' and 'Kindness to All Creatures Kick' and a booming, intimidating voice count as pacifism.  Fortunately, he rarely quests with the gang, thus keeping them out of the trouble his big mouth can cause.
Xelloss the Trickster Priest travelled with the group during Slayers Next and Slayers Try.  He's very amused by the world in general, very secretive, and also happens to be a dark general of the evil Mazoku (in the dub, Monster) race under the Beastmaster who is under Shabranigdu (whacked in Vol 3. of the Slayers) who is under the Lord of Nightmares..... needless to say, he's a bad man.  But he does like a good joke and will help the gang out, provided that doing this helps his own goals.  Will he show in Reflect? "That is a secret."
Luna Inverse, Lina's older sister. We never meet her, and this is one of the only two pictures available of her.. but apparently, she's VERY POWERFUL, works part time as a waitress and part time as a knight of Suffeed the Dragon King, and Lina is scared to death of her.  Not much else is known about her, but mentions of her pop up from time to time.
The Lord of Nightmares, the creator of all, the ultimate force of chaos.  Generally avoids the mortal world, which is a good thing, because the few times Lina summons her as a destructive force with the Giga Slave spell, all sorts of badness go down.  Despite the dark name, it's largely assumed that L-sama isn't evil... just limitless and chaotic.
Story copyright 1998 Stefan Gagne, characters copyright H. Kanzaka / R. Araizumi.
A Spoof Chase Production.