Nerve Exhaustion

 is an active skill that can be taught to Sorcerers at level 56. It cannot be ranked up.

can be performed with a disc by the Sorcerer to silence up to 4 opponents. This is extremely useful in PvP; the only thing opponents would be able to do is run, making it a good time to stun/immobilize them to set up a huge damage combo. It's most useful when cast on opponent healer.

Note that as description says, this skill can only be used in PvP. If you're only doing PvE and running dungeons, there is no need to even hotkey this skill.

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

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.)