From LSWiki

Always true.

Class: Combat Skills
Attribute: Perception
Pedagogy: Physical Training
Practitioner Term: Killer

This skill represents one's trained or inborn conditioning to go straight for the kill in combat, striking hard and fast at the
most vulnerable point without flinching or holding back, and without indulging any notions of fair play.  It improves the damage
and accuracy of one's combat maneuvers.

Development Information: The killer instinct skill was created by Chaos and is maintained by Lost Souls; the source code was last
updated Thu Mar 03 02:17:54 2016.

Notes

• Increases capacity for emotive energy
• Decreases capacity for intellectual energy

Trainers

Avalon: Bercilak
Caern Argnash: Eldest Ruggsh (Caern locals and garou only...maybe.)
Gezuun: Xavok
Obsidia: Goth
Quetlatl: Jilae wanders
Shadow Tower: Boko
Storm Rock: Mor'guth
Association required:
Kazarak/Kazarzeth: Urdo Wanders
Losthaven Guard: Sthainath
Maidens of the Spear:  Sulin
Sodality of the Nine-Spoked Wheel: Grendal
Synodia Lykouros: Karth the Elder
Weapons of Vengeance: Varn
Guild required:
Aisenshi: Musashi
Battleragers: Borulien
Brute Squad: Fezzik
Coven: Leah
Coven: Lynda Xenetha
Hawkmen: Katar
Justicars of Axa: Edwin
Justicars of Axa: Merianna (Questors too)
Hantaka: Hasan Wanders
Ordo Ignis Aeternis: Iklam wanders
Ordo Ignis Aeternis: Badlokk wanders
Reapers: Holton Jax
Verynvelyrae: Sirinil
Quest required
Meziris wanders
Iaocia: Dolhand