Dark Souls 3 is all about, well Souls. As you play through the game, slaughtering anything and everything that is unfortunate enough to get in your path, you’ll collect thousands upon thousands of Souls. Most of these are your normal, every day variety, which you will take back to the Firelink Shrine and use to level up your character. Some are special though. After you beat bosses in Dark Souls 3 they will give you their Soul. You then have to make a choice, use them and gain a massive amount of one-time Souls, or actually put them to their proper use and create an item of permanent value. Leading to the question, “what to do with boss Souls in Dark Souls 3”.
We’re here to answer that very question, in fact we’ve already answered it somewhat in our “how to use the Transposing Kiln” guide, which you can check out right here. So, what do you do with boss Souls in Dark Souls 3? Well, if the name of that guide wasn’t a big enough hint, you transpose them. Transposition takes the boss Soul and turns it into another item, which is unique to each individual Soul. Some are free, costing just the Soul itself, while others cost even more of the normal type of Soul.
For the full details you should check out the guide linked above. The short answer is to head back to the Firelink Shrine and speak with Ludleth. He’s the tiny guy sitting on one of the Lords of Cinder thrones above you. He’ll need a special tool though, which you can get by beating the Curse-Rotted Greatwood (find out how to do that right here). This item is the transposing kiln that Ludleth will use to transpose the Souls into whatever item they can become.
Dark Souls 3 doesn’t really tell you directly what to do with boss Souls, so it makes sense that so many are confused. Hopefully this sets you on the right path, but be sure to view the other guides for more in-depth info on each step of this process.