You don't, I think you misunderstood. Serena removed a tiny portion of your soul so you'd be able to survive in the Soul Cairn. This has no effect on you normally, it just means that you can enter the Soul Cairn safely, though weakened rather than killed outright. There's no need to get the piece of soul back.
Kill a dragon walk up to it and stuff flys at you that is the soul. And then it says Dragon soul absorbed
Dragons peak
dragons peak on 1st pounce pads
Sorry I don't know but I know where Sunburns soul gem is it is in Dragon's Peak about 5 minutes into it lean of the island and there is a dragon waiting there to take u to his soul gem
GET soul gem and unlock the soul gems upgrade
you find sunburns soul gem in his adventure packs level
Darklight krypt is where you find sunburns soul gem
I'm pretty sure you find it in dragon's peak which you have to buy to unlock and it comes with sunburn.
That would most likely be black. However, There is no way to trap a dragon soul in a soul gem. They are impervious to soul trap of any kind even when using the restoration exploit. I don't want to explain further due to spoilers.
Whirlwind's soul gem is on Chapter 17, Creepy Citadel. After the little goblin puzzle, there is a platform with two Gargantulas. Defeat them to open the gate and get the soul gem. Hope this helped.
you find the soul gem in darkwater cove but i dont know the exact place in the level
if it is for skylanders dragon's peak is out now i really want it :)
its on oilspill island