Monk's fist of [element] ideas

[Sylkis]

I want to make the fist of [element] skills more interesting.

All fists of [element]:
Removes greased lightning and grants stacks of fist of [element] equal to the level of greased lightning. Passive effect wears off when all stacks are consumed. Cannot be used with other fists and shares recast timer with them. 30s recast

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Fists of fire
Passive: increases damage dealt by 5%.

Skills that can consume fist of fire stacks:
Howling fist - converts to conal AoE
Featherfoot - deals an attack back to the attacker at 250 potency. Lasts for 15s or 1 hit as a separate buff to the evasion buff.
Shoulder tackle - deals damage and stuns all enemies between you and the target, including the target.

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Fists of wind
Passive: increases movement speed by 10% and increases evasion by 10%.

Skills that can consume fist of wind stacks:
Arm of the destroyer - inflicts silence regardless of stance.
Featherfoot - 50% chance to reset Featherfoot cooldown on evade.
Shoulder Tackle - cooldown is not activated
Mantra - also increases movement speed of you and nearby party members by 10%
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Fists of earth
Passive: decreases damage received by 10%.

Skills that can consume fist of earth stacks:
Featherfoot: also reduces damage taken by 10%
Second wind: also heals nearby players
Mantra: also reduces damage taken by you and party members by 5%

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This may seem to make monk overpowered, but how potent each ability is can be adjusted.

Thoughts?