Eclage Dungeon is a three-level dungeon where customized MvPs Soul Taker and Firefox reside. There are more customized dragon mobs in this dungeon in addition to the ones in Eden Dungeon.
You can find Soul Taker in the first two levels, and Firefox in the third level. After submitting Lost Soul, talking to the Solider in Bastion will automatically warp you to Eclage Dungeon [Lv:2] (ecl_tdun02) instead of [Lv:1] (ecl_tdun01). To unlock Eclage Dungeon [Lv:3] (ecl_tdun03) (Firefox Dungeon), you must first submit Lost Soul then talk to General again and submit the three items that he requires. You do not need to summon Soul Taker as he is not a chapter boss, but you will need to summon Firefox in [Lv:3] ecl_tdun03 by killing 400-600 mobs.
WARNING: Your character will be locked out of Eclage Dungeon after it kills the summoned version of Firefox 7 times.
Getting to Eclage Dungeon
There is a portal in the third level of Eden Dungeon that will take to you Bastion, where you must walk to the right and talk to the Soldier in order for him to warp you to Eclage Dungeon.
Visit the Eden Dungeon page for instructions on how to get to Bastion. Then, visit the Bastion page to know how to get to Eclage Dungeon.