Please see Mirrah Set instead.
and that a lot of its story and lore were executed poorly, but it's nice that Dark Souls 3 doesn't pretend it didn't exist. The Giant tree at Firelink Shrine, Yhorm the Giant, and Lucatiel's set. It's nice to see that Miyazaki appreciated Yui Tanimura's efforts to carry the torch in his absence and thus is integrating Dark Souls 2 into the canon by bringing back parts of it. That said, I'd like to see how Drangleic is going to fit into the picture and that if there will be more references to Dark Souls 2 as I play.
In my play through, I found the chest, legs, and hands all at the bottom of a tower in the Undead Settlement. The tower is to the right of the path that leads to the Curse-Rotten Greatwood. I personally stumbled upon it after helping Seigward kill the demon, I continued that path until I saw a cliff to a tower (me being an assassin, I used spook and jumped). This tower has the rest of the Mirrah set in it.