Whirlpool is actually one of the best skills to start on-striking proc chains.
Specifically for
Nimmenjuushin
Nimmenjuushin
War Axe (Sacred)
One-Hand Damage: (98 - 110) to (221 - 284)
Required Level: 100
Required Strength: 464
Item Level: 105
Strength Damage Bonus: (0.11 per Strength)%
8% Chance to cast level 10 Claw Tornado on Striking
+(4 to 5) to Druid Skill Levels
+12% Bonus Damage to Mark of the Wild
(151 to 175)% Duration Bonus to Mark of the Wild
30% Attack Speed
50% Hit Recovery
+(101 to 150) to Maximum Damage
(8 to 15)% Life stolen per Hit
+(115 to 140)% Enhanced Damage
(21 to 30)% to Strength
Requirements -20%
Socketed (6)
amazon, who doesn't have access to a multihitting WDM attack while using an axe (unless you count War Spirit, but it's not reliable).
It's important to use it in a big crowd of monsters for the best possible effect. So done right, you can clear Bremmtown by using Whirlpool.
I believe I've done that with an assassin, since none of the other specs worked out for me.