Cleon
Legend
Blue Fire Giant
So are any of those quibbles of use to you?
As you can tell I have way too much spare time this Sunday!
Moving on to the stats, they look pretty good but I still have a few suggestions.
How about adding Dexterity to the Saving Throws? Then they'll have one save proficiency from the Fire Giant parent (DEX), one from the Storm Giant parent (STR) and one both parents have (CON).
The lack of Skills really stands out.
Fire Giants have Athletics & Perception.
Storm Giants have Arcana, Athletics, History & Perception.
How about Arcana, Athletics & Perception for the Blue Fire Giant?
Now for the special traits, which begins with Burning Aura.
Firstly, it is strange that the aura cannot injure creatures without metal armour but still ignite wood and melt rock - the trees and boulders aren't wearing metal armour!
Presumably it being more harmful to metal armored creatures is somehow connected to their Crafting Magic only crafting metal, but I think creatures who don't wear metal armor should be able to take at least some damage from it. Maybe give them advantage on the saving throw instead, or give metal armored creatures disadvantage on the save?
Secondly, said save seems curiously low at DC 10. Presumably it's using the Blue Fire Giant's lowest stat of CHA 7 (-2) for the save and a base DC 8 like a spell?
Thirdly, there's a typo ("exstends") in the 2nd sentence and the final sentence has an extraneous comma ("resistance, or immunity") and an "effected" that should be "affected" (i.e. it should be "Creatures with fire resistance or immunity are not affected by the exhaustion."
As for Crafting Magic, I notice a few minor typos plus a couple of suggested tweaks I present below:
Crafting Magic. The blue fire giant conducts a 10 hour-long ritual that crafts a nonmagical item that must include some metal. The creation is completed at the end of the hour, coalescing in an unoccupied space of the giant's choice within 40 feet.
The item the giant creates can be worth no more than 5,000 gp, weigh no more than 3,000 lb., and must have enough space to coalesce. As part of this ritual, the giant must lay out metal, which can include coins, with a value equal to the creation. The metal transforms into the item at the ritual's end, magically forming even nonmetal parts of the creation.
The ritual can create a duplicate of a nonmagical item that contains metal, such as a key, if the giant possesses the original during the ritual.
Next, in Molten Skin it should be "AC" or "Armor Class" rather than lower case "ac".