This comment doesn't take into consideration all the OP dark DPS units that exist. Considering, furthermore, that the dark units have a natural advantage over the light units this buff has been long overdue. WOL is easily taken down by KoR, Kain and Vinera. Gumi is balancing the game because the light units haven't had anything spectacular since WoL - even Thancred (who is a 100 cost) is average.
It's all good, mate. Cid has had two buffs already - those being coral sword and aignon esper and card. He was already strong, but they are definitely keeping him at the top of the meta. The lightning elemental class has a high bar to scale because of him :)
I don't see how Dark is OP over Light. Light units are also advantageous over Dark units. Furthermore, I've yet to see any Dark units with the Master Ability which grants the party "+ Dark Attack", so I honestly don't understand why people still dares to say that the current Light elemental isn't OP, with there being top grade Light Tanks, Healers, and DPS.