Mindblast

 is an active skill that can be taught to Sorcerers at level 24 and can be ranked up at later levels.

can be performed with a disc by the Sorcerer to cast an AoE sleep effect. The long cast time can be slightly offset by first using Time Gyre. This skill can be used as CC or as an interrupt (ie. to a BAM).

Duration of sleep varies dependent on skill rank.

Rank table
To obtain and upgrade, 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.)