Name: ValgaavName: ValgaavVal was the sole survivor of the Ancient dragons after they were killed off by the Gold Dragons for safekeeping a Weapon of Light. Battered and bruised he encountered Gaav, who promised him revenge if Val would become his follower. Val accepted and then was killed by Gaav and reborn as a mazoku (and in turn Val took on the name Gaav = Valgaav.) As everyone knows (well, for those who've seen NEXT) Gaav was killed by Hellmaster Phibrizzo, who used Lina Inverse as bait to lure the rebel lord to his destruction. Because of this, Valgaav has made it his sole purpose in life to avenge Gaav by destroying Lina. He is also employed by Almayce to find the Weapons of Light, but Valgaav usually disobeys orders to do what he wants, either go after Lina and Co. or avoid Xellos-who's mission it is to destroy Valgaav. Valgaav is quite destructive by nature, wanting to lash out at the world that has been so cruel to him. Near the end of TRY Dark Star manages to get through the gate and consumes the willing Valgaav. But he is not killed. Instead he becomes Dark Star's messenger (so to speak) and using the god's power, wipes out the Gold Dragons. Of course since this is Slayers, Dark Star is beaten back to where he came from, and Val is reborn as an egg to get a second chance at life. Filia takes it upon herself to raise him, perhaps to right the wrong that her race did to the Ancient Dragons.
*A side note. Perhaps the main (and most likely) reason Valgaav has trouble transforming into his dragon form is because a) he never learned how to fully transform (as can be seen in the flashback Filia sees of the genocide of the Ancient Dragons.), and b) he is part Monster, which is the complete opposite of the dragons (they're considered to be the god's race). Basically his body is incompatible with itself (which would explain his long periods of agony when he attempts to transform.)
Wataru Takagi (Japanese)
Scotty Ray (English)