Here is the custom runeword I made, feel free to submit yours!
Nightmare
‘HelChamFal’ in 3 socket helms and shiels
10% Chance to cast level 15 decrepify when struck
Level 30 thorns aura
+1 All skills
30% Enhanced Damage (Helmet Only)
+10 All resistances (Shield Only)
+10 Strength (Fal)
Cannot be Frozen (Cham)
-15% Requirements (Hel)
5% Experience
8% Damage reduction
+15 All resistances
(I tested this runeword in both helm and shield in singleplayer using hero editor and the thorns aura was almost useless, but the decrepify felt nice. I think if this was a real runeword it would be used on helm for act 2/5 merc)