Path of Trag'Oul is a Unique Boots in Diablo IV Season 15. It comes from Duriel, King of Maggots (Lair Boss) per one guide; Random world drop / any Lair Boss (one guide: 'drops at any Difficulty Tier, increased drop rate per Torment tier'); 3.2.1: all Uniques drop from level 1 in any Difficulty; targetable via Horadric Cube reroll.
Unique power
Bone Prison traps a larger area and fires [30 - 35] Bone Splinters at enemies trapped within. Your Maximum Essence is increased by 2 for 10 seconds each time these Bone Splinters hit an enemy.
Affixes
+1-3 to Bone Prison
Where it drops
Duriel, King of Maggots (Lair Boss) per one guide
Random world drop / any Lair Boss (one guide: 'drops at any Difficulty Tier, increased drop rate per Torment tier'); 3.2.1: all Uniques drop from level 1 in any Difficulty; targetable via Horadric Cube reroll