Rictus of Terror is a Unique Helm in Diablo IV Season 15. It comes from Duriel (Lair Boss loot table); Duriel (Lair Boss loot table, boosted class-unique drop).
Unique power
Command Laalish is now an Ultimate Skill and deals [100 - 120]%[x] increased damage. Command Laalish's Terror Realm lasts 50% longer and, while you are within it, your Abyss Skill casts do not break Shadowform Stealth.
Affixes
Willpower
Cooldown Reduction
Where it drops
Duriel (Lair Boss loot table)
Duriel (Lair Boss loot table, boosted class-unique drop)