Soul seed

Soul Seeds are key items in Lightning Returns: Final Fantasy XIII: they are items which spawn monsters and are made up of the souls of the dead. They appear as shining purple lights on the ground within Chaos infusions, and remain for a time after the infusion has been dissipated.

Collecting seeds earns achievements and trophies. The number of sold Soul Seeds do not carry over to a New Game+. Because they are key items, seeds in the inventory will also be lost.

Baird's Tale
The Order buys the soul seeds from Baird, and use them for experiment and research. He tells Lightning that soul seeds are human souls, and monsters are humans that failed to be reborn. Both monsters and humans have the same origin; both are born from Chaos. Baird explains the soul seeds have an effect on souls, and that there was an alchemist who tried to infuse a soul seed to a machine but the experiment was a failure. Though Baird doesn't know where the alchemist resides these days, he says he's heard rumors that they still dapple in the dark arts.

Ramira's Tale
An alchemist, believing that soul seeds are what humanity lost when the Chaos was released, swallowed a potion he made using soul seeds and then proceeded to throw himself in to the Chaos.

Kaj's Tale
Once a blacksmith forged a weapon with a soul seed. That weapon turned on its creator by killing him. The weapon disappear, and this weapon's name is Ultima Weapon.

Mal's Tale
An alchemist tried to create a new human life with a soul seed, but this homunculus wasn't remotely close to being a human.

Profile
Soul Seeds are found within Chaos infusions and are said to come from the souls of dead humans and be the eggs from which Chaos monsters are born.

Since Chaos infusions appear randomly across Nova Chrysalia, the fastest place to farm Soul Seeds is during the Death Game quest in Yusnaan, which makes an area of the city a permanent Chaos infusion area until that quest is completed. If the player purposefully forgoes completing the quest until late in the game, they can keep going to the quest area to battle Chaos monsters and find Soul Seeds. Another good place with plenty Chaos infusions are the Highroads, but they are very dangerous due to the toughest monsters of Nova Chrysalia residing on them. The Highroads cannot be unlocked until Day 9 when the corresponding Canvas of Prayers quests become available.

The spawn of Soul Seeds is time-related, which means the player must wait in-game time and let the clock advance to make them spawn. If they use Chronostasis, they'll block the respawn of Soul Seeds. Average rate is two Soul Seeds per hour of the day. To make the Soul Seeds appear, the player usually must win a battle, although single Soul Seeds sometimes spawn even without enemies. To farm Soul Seeds the player wants to wait for about an hour, fight an enemy to make the Soul Seeds appear, and go collect them. The player will have to wait one in-game hour since the time the player collected the first Soul Seed.

For the 5-4 What Soul Seed Traders Want main quest, Lightning must contact any of the traders and bring them a Moogle Fragment.

Merchants
Soul Seeds Merchants, also known as Seed Hunters, are the sole buyers. Before the player can sell them, they will need to complete the Side Quest Soul Seeds in Luxerion. This quest is given by Baird, one of the four merchants, and it can be completed rapidly when the player gives him 2,000 gil and sell him a Soul Seed at any time. The merchants are easily recognizable by their Black Mage-type hats, the name and location of the merchants are:


 * Baird in the Arcade area of Luxerion standing next to a pillar.
 * Ramira in the staircase between Central Avenue and the Industrial Area in Yusnaan.
 * Kaj next to the sheep pen in Aryas Village in the Wildlands.
 * Mal inside the Ruffian's den in the Dead Dunes.

Soul Seed sells for 400 gil a piece, but if the player sell enough Soul Seeds they will receive a special reward for every 20 Soul Seeds sold. These rewards are cumulative, the table below list the rewards obtained the first time the player sell that amount of Soul Seeds, and the second (and following) time they do so.