@Kraco:


[Plenty of info from previous seasons/movies and a little bit out of the books (the books are slightly different and give more details than Slayers and Slayers NEXT do)

It's not unusual at all for more than one person to use the Dragon Slave. A lot of people in the old series could use it, Lina was just very well known for having no sense of restraint on what is essentially a nuke. In fact, back in season 1, Lina taught Amelia how to use it, who leveled a burial mound. It was weaker, but that was understandable. Then, at the end of season 2, Sylphiel revealed she had learned to cast it. More specifically, specialized in it. So much so that Lina, even when her magic was boosted by the set of talisman she bought off Xellos, was not able to match Sylphiel's version.

As for the Rah Tilt, Amelia was strong is white/shamanistic magic in addition to meddling in black magic, while Zelgadis only used shamanist magic. The Rah Tilt is the pinnacle of Astral spells (detailed in that episode of season 1) so I suppose that somehow puts it between white and shamanist magic.

As a sidebar about the Giga Slave, that one is unique to Lina. There has been speculation in the past that Lina was a reincarnation of the Lord of Chaos, just as her older sister had a shard of Sylfeid (the water god who fought to the death with Shabernigdo) inbedded in her, and leading to the reason Lina is so terrified of her sister.