Kartik
Actually ,I missed my dark slayer. I couldn't play more massively by current sword. Skills including...

I couldn't understand what you are saying about "2nd dark slayer.. do you mean 2nd dark sword or 2nd unique full set? The meteor storm takes a longer time to cooldown than sword quake but it can inflict double damage when used. You just have to find armors with better cooldown to decrease the cooldown of all your skills. Use also the reset options in your sword and find one that has a cooldown highlighted in blue. This may sacrifice other stats and couldn't get what you desired most but you have a choice in here. Or if you don't like that then buy skill transfer card. Change your skill with a better cooldown.
I have here a sample of an exceptional Dark helm with good cooldown