Fearsome Shout

 is an active skill that can be learned by Berserkers at level 46 and can be ranked up.

can be performed with an axe by the Berserker as a sort of an interrupt. The usage is more appropriate for group PvP, when you want to scatter a group of enemies. This skill is not recommended for when fighting bosses or BAMs in a party, as it would make the target run off in a random direction, frustrating your tank and possibly getting a party member killed.

It is unclear from the skill description what the effects of ranking up the skill are.

Rank table
is purchased from Tactic Instructors. This skill cannot be upgraded.

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 berserker 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.)