From wow.incgamers.com

Statistics

• This skill requires the Elemental Mastery Talent

Talent Improvements

Elemental Tree

Talent: Elemental Mastery Talent
Effect: When activated, this spell gives your next Fire, Frost, or Nature damage spell a 100% critical strike chance and reduces the mana cost by 100%.
Statistics: N/A

Threat Level

This skill causes no amount of Threat.

Uses in PvP

Please feel free to add a bullet list of uses within PvP or editorial if you have more to say. What use is it against other builds, what skills can it be used to counteract or prevent. What skills does it work well in combination with.

Uses in PvE

Please feel free to add a bullet list of uses within PvE or editorial if you have more to say. Which creatures/bosses in particular is it useful against. What skills does it work well in combination with.