For people who are still confused by this info “Increases damage calculating formula of Crystals by 20%” in Oct 31st 2012 Patch notes.
I want to make it clear:
1, The formula here changes the way for calculating the output damage of Crystal
2, The damage will be calculated for every crystal you equip
3, Each crystal will get 20% boost of output damage
4, For WI/FA : Using crystal means you have to spend stats in DEX/STR that will decrease INT (means Magic Attack)
5, The damage won’t show up in stats of crystal or as Magic Attack/Attack, only changes as the output damage (the number in bracket ( and ) in Character info window – shortcut C)
Hope this helps 🙂