From LSWiki

Class: Combat Skills

Attribute: Perception
Pedagogy: Physical Training

The ability to fight effectively without being able to see one's opponent, by 
relying carefully on one's other senses.  Though most often used when fighting 
in the dark or blinded, this skill is equally applicable to fighting invisible 
opponents.

• Notes

Trainers

Trainers: 
Darkhold Tusk
Nexus: Goth
Wandering Lhethan Hagal

Association required:
Maidens of the Spear:  Sulin
Guild required:
Aisenshi: Musashi
Hawkmen: Shayera
Justicars of Tyr: Edwin
Justicars of Tyr: Strom Thromgald 
Ordo Ignis Aeternis: Iklam Wanders
Ordo Ignis Aeternis: Badlokk Wanders Skarlan
Nizari: Hasan Wanders
Quest required