Here is the full list of all 34 Omensight trophies - there are 22 bronze, 5 silver, 6 gold and 1 platinum.
Unlock all other trophies
Execute two Lethal Flurries in a row
Throw a bomb towards a column while inside Delay of Fate's sphere
Use Lethal Flurry 20 times
Break a barrel thrown by a Shark while it's in the air, by throwing a barrel at it
Launch a Phantom Blast on an enemy thrown with Phantom Grasp, while inside Delay of Fates' sphere
Jump on the head of all your companions
Kill four enemies with the same column
Unlock all bonuses at the end of a day
Emprison Voden
Launch 4 Phantom Blasts while inside Delay of Fate's sphere
Unlock the Kladen Seal
Defeat Ludomir in battle
Use Phantom Grasp 50 times
Defeat Draga in battle
Unlock all Harbinger's Blade upgrades
Unlock the last Omensight
Unlock all Harbinger's Aegis upgrades
Unlock Vera's Seal
Use Companion ability 50 times
Use Phantom Dash 30 times
Use Delay of Fate 20 times
Kill 100 Rodentian fighters
Unlock your second Omensight
Use Phantom Blast 30 times
Unlock the Rodentian Seal
Kill 100 Ciphers
Kill 100 Pygarian soldiers
Defeat Indrik in battle
Unlock your first Omensight
Defeat Ratika in battle
Unlock the Pygarian Seal
Kill a surrendering enemy
Witness Voden's appearance for the first time