Doubles your Attack and adds Dark element to your damage (which I believe only positively alters damage; I've yet to see a foe take near as much as a regular attack with Darkness active than without)... it's a pretty rad-awesome move, especially in a first playthrough or NG+. Darkness + Berserk = LUDICROUS DAMAGE... but you lose HP for each hit.
Note that the Darkness augment is the SAME EXACT ABILITY DARK KNIGHT CECIL HAD... that is what you missed. --- ''Sage'' of The Denpa Men board (Completionist Medal of Honor: http://i48.tinypic.com/20gmued.jpg) 3DS FC: 1590-4884-9269 | Don't bother sending me Swapnotes.
I believe it does because if you use it on Octomammoth or the Mist Dragon, the word "Weakness" will pop up, indicating you've hit a weakness on them - both are supposed to be susceptible to Darkness based attacks.
I believe (but won't swear to it) that if you just use a regular attack on Mist Dragon, that "weakness" won't show up.
That being said, the Darkness element might be such a rare element that the Defense Node might not absorb it because there isn't an Eidolon that Rydia can use for it - which I think is the main purpose of the Defense Node absorbing elements - so you can still use summons without fear of Globe199 or whatever it might be called in this version.
I just used Darkness on a Mystery Egg (I'm looking at the pause screen right now) the only other enemy according to Action's Bestiary to absorb the Dark Element.
I attacked with Edge using Darkness, his swords are of course non-elemental. The attack did 6242 damage and the Egg did not absorb it.
So no apparently Darkness does not actually add the Dark Element to your attacks. That's kind of good to know. Although only two enemies absorb Dark, quite a few resist it. But they won't resist Darkness because it's not Dark. --- If life is a game, how do I enable God Mode?
Welp, my bad then. It just doubles your damage and makes you take 10% of your max HP in damage when you Attack for several turns. --- ''Sage'' of The Denpa Men board (Completionist Medal of Honor: http://i48.tinypic.com/20gmued.jpg) 3DS FC: 1590-4884-9269 | Don't bother sending me Swapnotes.