Lightning Returns: Final Fantasy XIII The Last One Standing is the only side-quest featured in the video game that can’t be completed in the first playthrough.
While the payout is big, if you wish to finish The Last One you will have to start the game on New Game +, by finishing the main story.
In Lightning Returns: Final Fantasy 13 The Last One Standing, your client will ask you to kill all Omega creatures in the game, but three of them spawn while playing the final part, during which you are not allowed to return, thus, you can’t turn-in the quest.
Because of this, you will have to exterminate the last three Omegas in the final area, and then restart the game on NG+.
Only then you can complete the quest, by talking to your client.
Description: “At the foot of the Oasis Lighthouse, Lightning meets a man called Zanford who claims to be the last researcher. Not the last remaining researcher he clarifies, but someone who investigates the phenomenon of Last Ones.”
Location: Dead Dunes
Rewards: 12000 Gil, Recovery HP + 160, Strength + 18, Magic + 16, Hermit’s Cap Adornment, Bladed Lance
The Last One Standing can be activated by talking to Zanford located near the Oasis Lighthouse, SE from Ruffian in Dead Dunes. After you trigger the quest, you will be asked to kill all Omega creatures in Lightning Returns: Final Fantasy XIII.
Note: There is a total of 31 Omegas you have to defeat for this quest, along with Ereshkigal and Cactair.
Once you receive the quest from Zanford you have two options. The first one is to make an Omega spawn, by killing a large number of enemies belonging to the same species.
If you completed Free Will side-quest, or even better, Skeletons in the Closet, you already know that the Omega Skeleton appears after you defeat 60 Skeletons. The same rule applies for other Omegas, but for some of them you will need to defeat a larger number.
This task consumes time and at some point it leads to frustration. As an example, to make the Omega Meonekton spawn, you have to kill more than 5000 Meonektons.
The second option, which is also the recommended one, is to enter the Ultimate Lair, where you will find all Omegas.
The Ultimate Lair is a special location in Dead Dunes, and is unlocked starting Day 13, but only if you complete all main quests, and at least 40 side-quests. When you return to the Ark, at the end of Day 12, the moment you try to leave, you will be asked if you wish to enter the Ultimate Lair.
Even if you choose not to, you will still be able to reach it, by visiting the eastern Giant’s Sandbox, looking for a red Cactuar statue, very close to the Temple Ruins. Before entering; however, make sure you restock on all recovery items, and keep in mind that once inside, you will not be able to use the Chronostasis ability to stop the time.
Since this location becomes available on Day 13, you have to reach the final floor as soon as possible, or you will fail to complete it. In other words, you have to defeat all Omegas in one day, because the time also flows during a fight. The Ultimate Lair features 33 floors and 28 of them have Omegas, or Last Ones.
You will start at Lvl. 1 where Omega Hoplite is located, and descend using the Cactuar statue close to your enemy.
Note: All Omegas drop important items, so make sure you pick them up. If you defeated an Omega enemy while exploring the world, it will not appear inside the Ultimate Lair Dungeon.
The following list reveals all Omegas in Lightning Returns: Final Fantasy XIII Ultimate Lair Dungeon.
Lvl. 1 – Omega Hoplite
Lvl. 2 – Omega Niblet
Lvl. 3 – Omega Zaltys
Lvl. 4 – Omega Gaunt
Lvl. 5 – Omega Gremlin
Lvl. 6 – Omega Dreadnought
Lvl. 7 – Omega Gorgonopsid
Lvl. 8 – Omega Goblot
Lvl. 9 – Omega Gurangatch
Lvl. 10 – Omega Ectopudding
Lvl. 11 – Omega Miniflan
Lvl. 12 – Omega Aster Protoflorian
Lvl. 13 – Omega Schrodinger
Lvl. 14 – Omega Goblin
Lvl. 15 – Omega Reaver
Lvl. 16 – Omega Meonekton
Lvl. 17 – Omega Cactuar
Lvl. 18 – Omega Triffid
Lvl. 19 – Omega Cyclops
Lvl. 20 – Omega Skeleton
Lvl. 21 – Omega Desert Sahagin
Lvl. 22 – Omega Earth Eater
Lvl. 23 – Omega Skata’ne
Lvl. 24 – Omega Hanuman
Lvl. 25 – Omega Zomok
Lvl. 26 – Omega Dryad
Lvl. 27 – Omega Rafflesia
Lvl. 28 – Omega Chocobo Eater
Lvl. 29 – Empty
Lvl. 30 – Empty
Lvl. 31 – Empty
Lvl. 32 – Empty
Lvl. 33 – Ereshkigal
After you have defeated all Omegas within the Ultimate Lair, you have to find the last three during the The Final Day.
Note: While Aeronite (What Rough Beast Slouches) doesn’t count for the quest, Cactair (located close to Oasis Lighthouse) counts, and you have to defeat him as well.