If you want to get Thunder Breathing in Roblox, you will need to find a man called Kujima in Demonfall. Kujima can be found inside his house in the coast forest.
To find his house in the coast forest, start at the gate of Hayakawa village and follow the road north - if you look right, you will see a sign pointing north with coast forest written on it.
You will want to keep heading north until you see another set of direction signs, and after you find the next set of signs, turn right and keep heading down the road.
Keep heading down the road until you see another gate similar to the last one. When you reach the second gate, you will want to turn left and keep heading down the road.
Eventually, you will find Kukima inside his house next to a Wisteria Tree, and talking to Kujima inside the house will start the process of getting Thunder Breathing, which requires you to complete the following set of tasks.
- Get 20 soup
- Deliver a letter to Maronne
- Give 4k Yen
That said, if you need help completing the quest, we explained all of the steps required to do so in our guide How to get Thunder Breathing in Roblox Demonfall.