Return of Reckoning

Hey guys,
My idea is like this
issue:

current shaman class mechanic

proposal

if you are casting damaging spells, you have a 5% chance to proc your current class mechanic for damaging spells only for 5 seconds, and same goes vise versa for healing spells.

summary

spamming damage -> 5% proc damage waaagh -> 5sec activate
spamming healing ->5% proc healing waaagh ->5sec activate

in my opinion that way it wont be abused, and the mechanic can be useful now
What do you guys think.

Thanks.