Vasily's Prayer is a Unique Helm in Diablo IV Season 15. It comes from World drop (any difficulty, drop rate scales with Torment tier); Horadric Cube: Item Transmutation (Upgrade to Unique) - Common item of the same slot + 1 Enhanced Primordial Dust + 10 Primordial Dust (random Unique of that slot).
Unique power
Your Earth Skills are now also Werebear Skills and Fortify you for [2.0-5.0]% of your Maximum Health.
Affixes
1,200 Armor
+[1-1,450] Maximum Life
+[2.5-21.3]% Willpower
+[35-94] Willpower
+[91-1,225] Armor
Where it drops
World drop (any difficulty, drop rate scales with Torment tier)
Horadric Cube: Item Transmutation (Upgrade to Unique) - Common item of the same slot + 1 Enhanced Primordial Dust + 10 Primordial Dust (random Unique of that slot)