This is quite a good item. Moons comments about the effects on the character is a good one - being in literal Hell should leave a mark.
I would at least have the user now have infernal _attention_. It is not often that a soul gets to leave that place. I'm reminded of an old Dragon magazine comic that showed a character who managed to escape hell one time being waited for by a 'welcoming' committee after his final passing..
Contrary to the proverb about fighting in burning buildings, Reneth the brave (but stupid) fought a pitched battle during a raging forest fire against dark Giants. He succeeding in holding up their advance long enough for the firestorm to catch up with him and his opponents, allowing the flames to claim the giants. He of course fell with the giants and although his body was scorched beyond recognition, his armor and sword survived and these are the prize of this tomb.
This tomb may only be entered when a natural forest fire rages either on it or reasonable close to it. Druidic magic may be considered natural, but the likelihood of one agreeing to do this is rather remote.
Once inside, the raiders will find themselves also in the middle of a raging forest fire. They will also find themselves in pitched battle with massive deformed giants who are also being damaged by the smoke and fire.
Should the PC's survive the battle, the firestorm will clear revealing the armor and weapons in a charred clearing.
The difficulty of the battle - how many giants, fierceness of the forest fire, etc, should be based on how powerful the retrieved armor and weapons are, as well as how hard it was for them to have the forest fire that opened the tomb. Go to Comment
Final scene has Conan lifting the Black priest, with sword, dagger and other wounds aplenty, being hurtled bodily onto his own altar, upsetting the chalice and splashing his life's blood over the floor.
His own ghoulish followers, following their own infernal appetites, fall upon the spilled feast while the priest lies, broken and in his death throes.