Quote Originally Posted by sanahtlig View Post
If you raise it to SL20, yes, it'll be useful regardless. If all you want is the Soul-skill bonus and the excellent weapon skill bonus, one copy is sufficient. And in fact, getting a weapon for each of your 2-3 most commonly used Souls is probably a good idea before further investing in a single one.

I guess I should start farming these idea cores from Expert Disasters. The problem is... I'm still not sure what element I'm ultimately going to main. I was planning to max out my Wind team's assault and see how it fares in Ragnarok Advents compared to my Water team to help me decide.
I've heard that the drop rate is pretty much the same for the standard and expert disasters, at least for the discoverer and mvp chests. Is there a reason to do the expert disasters? Or do you mean do them in addition to the standard ones?