Slayers (1995) : 3x21

Lina and the gang reach a temple, which turns out to be an anicent temple for the graves of the Anicent Dragons, that was slaughter by the Golden Dragons. It is sealed off by several magical barriers that Filia could easily break through. Except for one that was sealed by the Anicent Dragons themselves, holding the final weapon. We learn the back story on why the Golden Dragons killed the Anicent Dragons, they feared their power and that's why all (except Valgaav, who escaped) was killed. While this is happening, Xellos has a plan on his own, he decided to befriend Sirus, in an attempt to bring back Dark Star. Almayce tries to talk to Xellos about this, while Lina and the gang fight of Erulogs, except for Filia who is trying to get the the final weapon. To Lina's shock all of the Golden Dragons appear.