bronze:

Learned The Reverse Wind
Successfully Perform The Reverse Wind Technique

Learned The Furious Wind
Successfully Perform The Furious Wind Technique

Learned Shadowless Footsteps
Successfully Perform The Shadowless Footsteps Technique

Learned The Flying Swallow
Successfully Perform The Flying Swallow Technique

Learned The Flying Bird Flip
Successfully Perform The Flying Bird Flip Technique

Learned The Obliteration Technique
Successfully Perform Obliteration Technique

Learned The Ultimate Technique
Successfully Perform The Ultimate Technique

Learned The Ultimate Guidance
Successfully Perform The Ultimate Guidance Technique

Learned to The Counter Attack
Successfully Perform The Counter Attack Technique

Learned The Unrivaled Soaring
Successfully Perform The Unrivaled Soaring Technique

Learned The Invisible Path
Successfully Perform The Invisible Path Technique

Learned The Izuna Drop
Successfully Perform The Izuna Drop Technique

Learned The Guillotine Throw
Successfully Perform The Guillotine Throw Technique

Learned The Art of Inferno
Successfully Perform The Art of the Inferno Ninpo

Learned The Art of Wind Blades
Successfully Perform The Art of the Wind Blades Ninpo

Learned The Art of Flame Phoenix
Successfully Perform The Art of the Flame Phoenix Ninpo

Learned The Art of Piercing Void
Successfully Perform The Art of the Piercing Void Ninpo

Feat of a Hundred Slashes
100 Hit Combo With Any Weapon

Feat of a Thousand Obliterations
Defeat 1000 Enemies Using Obliteration Techniques

Feat of Ultimate Destruction
Defeat 1000 Enemies Using Ultimate Techniques

Izuna Drop Master
Perform 1000 Izuna Drops

Guillotine Throw Master
Perform 1000 Guillotine Throws

Dragon Sword Master
Defeat 1000 Enemies With The Dragon Sword

Lunar Staff Master
Defeat 1000 Enemies With The Lunar Staff

Falcon’s Talons Master
Defeat 1000 Enemies With The Falcon’s Talons

Dual Katana Master
Defeat 1000 Enemies With The Dual Katana

Kusari-Gama Master
Defeat 1000 Enemies With The Kusari-Gama

Eclipse Scythe Master
Defeat 1000 Enemies With The Eclipse Scythe

Tonfa Master
Defeat 1000 Enemies With The Tonfa

Vigoorian Flail Master
Defeat 1000 Enemies With The Vigoorian Flail

Enma’s Fang Master
Defeat 1000 Enemies With The Enma’s Fang

Ultimate Ninpo Master
Chant 100 Ultimate Ninpo Spells

Rescued 100 ninja.
Rescue 100 People In Need

Gold:

All missions successfully completed
Successfully Complete All Missions

Platinum:

Master Of The Secret Arts
Obtain all trophies.

plus another 16 trophies which i think are silver the most of them like maybe 2 gold and the rest bronze

source:

http://www.allps3trophies.com/retail-games/ninja-gaiden-sigma-2-trophies.html