you may also go for Ancient's hand oskill (converts physical damage to fire damage) on the switch attack to have acces to all 3 conversions . you can find it on
Anak


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Anak
Barbarian Swords, Barbarian One-Handed Axes
'HelEldBer'
Runeword Level: 78
30% Attack Speed
Adds (20 to 40)-(55 to 75) Damage
Adds 100-200 Lightning Damage
-15% to Enemy Lightning Resistance
+(171 to 200)% Enhanced Damage
Slow Target (10 to 15)%
Lightning Resist +(66 to 75)%
+50 Life on Melee Attack
(3 to 7)% Gold Find
Barbarian Swords, Barbarian One-Handed Axes
'HelEldBer'
Runeword Level: 78
30% Attack Speed
Adds (20 to 40)-(55 to 75) Damage
Adds 100-200 Lightning Damage
-15% to Enemy Lightning Resistance
+(171 to 200)% Enhanced Damage
Slow Target (10 to 15)%
Lightning Resist +(66 to 75)%
+50 Life on Melee Attack
(3 to 7)% Gold Find
Gilgamesh
or a crafted barbarian weapon . it also spawns on barbarian helms but i think you won't want to have that instead of kraken stance .