evolving ring 2013 event

I'm wondering how do i get the 15 att ring... do i have to wait till some special day?

also is it better than a 5% crit rate ring?

http://maplestory.nexon.net/news/events/...ring-event

"During the Rewards Phase (August 18 to September 2), you can earn a reward based on how many days you have participated in."

As for it being better or not guess that is up to you if you want the crit rate or more attack/all stat.

As for it being better or not guess that is up to you if you want the crit rate or more attack/all stat.

Presumably, he wants whatever will give him more DPM.
That depends on the stats one already has, though.