Mana Volley

 is an active skill that can be taught to Sorcerers at level 58. It cannot be ranked up.

can be performed with a disc by the Sorcerer. It is a very powerful skill for PvP, because you are draining their mana pools (and players' mana pools aren't that big). It is also useful for recovering your own MP in PvE.

Rank table
To obtain, one must find a Magic Instructor and pay a certain price of gold dependent on rank.

Glyphs
To glyph, a glyph must be obtained and learned only once. At level 60, a character has 50 glyph points available to spend on all available sorcerer glyphs. Most glyphs, specifically common glyphs can be purchased from a Glyph Master, while fine glyphs must be looted from enemies.

(Disclaimer: As NPC shop prices vary depending on a variety of factors, the prices below are subject to variation. Only take them as benchmarks.)