You'll fight Enki and Enlil on this Map. This is perhaps the most interesting boss fight so far, as you'll be taking on two powerful opponents. They are very similar, except that Enki uses Water and is vulnerable to Lightning, while Enlil is vulnerable to Water and uses Lightning. Enki may be a bit easier to kill since both Sazh and Vanille have access to Thunder, while only Vanille has Water (while Sazh can use Enwater after Enki falls). Both bosses are vulnerable to Deprotect, Deshell, and Poison. You certainly want to debuff the one you're concentrating on, but it can't hurt to Poison the other as well. Keep your health high and cure Deprotect if it is inflicted, and you'll eventually defeat one boss or the other, making the second half of the fight quite a bit easier. You may wish to alter your Accessory setup for this fight—giving Sazh a pair of Spark Rings can be especially effective.