Lightning Returns: Final Fantasy XIII Fireworks In A Bottle side-quest is one of the two quests that can be failed or missed, unless completed within the allotted time, and during the second main quest in Yusnaan (The Legend Of The Savior).
Fireworks In A Bottle, as well as Fireworks For A Steal, are connected to The Legend Of The Savior, and should be completed before the second phase of the main quest.
The following walkthrough outlines the steps you need to follow so you don’t miss the Fireworks In A Bottle quest and get all associated rewards.
Description: “On Yusnaan’s Central Avenue, a drunk pyrotechnician refuses to hand over any fireworks to Lightning. But if Lightning were to bring him a bottle of Yusnaan’s finest, he might be inclined to change his mind.”
Requirements: Start at 7 PM, end it before 11 PM, during Main Quest 2-2: The Legend Of The Savior.
Rewards: 300 Gil, Maximum HP + 40, Strength +2, Magic + 4, Ceremonial Headdress
When you start The Legend Of The Savior quest in FF13 Lightning Returns, you will be asked to find 10 fireworks for the Fireworks Boss.
The locations where you can find the fireworks are marked on your main map; however, you can also get fireworks from Chocobogirls or if you fight in The Slaughterhouse.
If you pick these two paths, avoid the pyrotechnicians, and continue the main-quest by giving the fireworks to the boss, you will miss the current quest as well as Fireworks For A Steal.
On the other hand, if you visit all pyrotechnicians including the one that triggers the current quest, and get the fireworks from them, you will miss the Fireworks For A Steal quest.
Note: The proper path to follow when you are asked to get the fireworks is to play Fireworks In A Bottle followed by Fireworks For A Steal, because you will get the necessary amount of fireworks without missing any quest.
Assuming that you decide to complete both quests, open your map after you talk to the Fireworks Boss and head to the technician located on Central Avenue. As you will notice, he is a little tipsy, and he doesn’t want to cooperate.
However, as Lightning tries to convince him, the drunk technician is willing to give her some fireworks in exchange for Yusnaan’s finest brew, or Bacchus’s Brew. At this point, to complete the quest you must find Bacchus’s Brew.
Open your map and head to the Yusnaan Station, then east to reach The Banquet of the Lord. The Banquet of the Lord is the best restaurant in Yusnaan and here you will find the Bacchus’s Brew, but you have to pay 1000 Gil to get it.
Talk to Banquet Maitre D’ and pay the required amount to get the drink, and then give the bottle to the drunk technician on Central Avenue for 4 Fireworks and to complete Fireworks In A Bottle.
Now, you should start Fireworks For a Steal which is also a missable side-quest in Lightning Returns: Final Fantasy XIII.