The Heartflame Set is a set of legendary artifacts, it is unknown how many parts there are of the set, in fact it is almost unknown that there is a set. While who the set was originally crafted for is unknown, considering the activation method for the breastplate, the individual was most likely a drake. Parts of the set are also considered a national treasure for the drakes, as would any other part of the set, if they were known.
Known Parts
Heartflame Breastplate
The Heartflame Breastplate is known as the Drakes national treasure that was lost for hundreds of years. It is now in Selys Shivertail's possession.
Helm of Fire
The Helm is only known through the Skill [Legacy Whispers: Heartflame Set].[1] The skill gave Selys Shivertail's some information in order to find its location.
To find the helm of fire,
Look to death’s ire;
That village without rest,
Where the Putrid One met his death.[1]
There are no innworld speculation on what village this verse can be pointing towards. There is one village in the northern part of Izril, not far from Dwarfhalls Rest, where the Undead never rest and never leave. The undead just defend the village and anyone that fall in the area raise again to continue the defence. Rags did attack the village with her tribe, but they where forced to retreat.[2]