Alcha was a hag of a giantess, her blood muddied with the bastard influence of mankind, how a man might mount a giantess, or a woman survive the lusts of a giant is a mystery, but it is simply what it is. By their standards, she is short, her spine deformed and her skull misshappen. By human standards she is massive and oddly proportioned, with gangley arms and stumpy legs and a face that would give a cow a fright. One of her eyes was clear, blue like a glacier lake, the other was cloudy and grey like storm clouds. Half-blooded and mystic marked it was no surprise that Alcha was exiled by both of her kins. The giantess lived a hermit's life in the swamps, her home on a stone rising from the bog. She crafted things, looked into the future through splattered entrails, and was occasionally called upon by sages, scholars, and Knight-Errant who required guidance. To this end, she crafted her great stone cup.
The Stone Cup Alcha's cup is made of a single piece of banded gneiss, a hard layered stone that is known for having large crystalline structures in the material. The cup is large enough to be a large bowl for a human, the sort a salad is served in for an entire dinner party. For Alcha it is a large cup. The workmanship is crude, as Alcha is not, nor will ever be, a gifted shaper of stone. The smooth surface of the cup is from years of use, both in the practice of magic and for commoner purposes such as the grinding of herbs for poultices and spices for food.
Allad Allap cursed the swamp for a third time as his white tunic was as badly soiled, likely ruined, as his white cape and his precious leather boots were now a completely lost cause. Why did the blasted giant have to live in the middle of a sucking morasse of filth and slime, and things that drooled constantly. He found it's mighty hovel and called the creature out.
"I am Allad Allap, the hero of Calana, the Warrior-Groom of Princess Samis of Turcha Castle, slayer of the Turchan Horror and son of Allad Allag. Giantess, seer, come forth and divine my future, for I am a-quest!"
Alcha sighed and brought forth the cup for another boastful human. At least the humans did not come with as many threats of violence as the giants did. "Fill this cup with water, and your future and your past will become plain," Alcha said, noticing the proud warrior in white flinching from her visage.
He did as instructed, and filled the cup with water from his drinking skin. "There is payment that must be paid," Alcha said, she looked into the cup and saw a future unfold in the banded stone. "Your firstborn daughter's name," "Your price is her name?" Allap asked. Alcha nodded, "You will give me her name and I will cast it into my cup and your future will become plain."
Allap said a name, forgotten as it left his lips and the surface of the water grew still as glass. He saw in it the future of his quest, of the beast he would have to defeat to gain his fame as a great hero. It was within his grasp, but he also saw the price he had paid, for his firstborn daughter would be born with the gift of magic, but she would forever be a stranger to him, and he an intruder to her.
The Power of Divination Something must be given to the Cup to activate it, this can be blood, a thing of power itself such as a jewel or similar item of value, or its most effective fuel, true names. The less valuable a thing given is, the useful the information given is. A small jewel gives cryptic glimpses of what may be, and very limited answers. Blood, or life can provide middling answers, the sort that is the most common sort of prophecy. Giving a true name grant clairvoyant power to see the future. Alcha has not seen the future as giving a true name is not easy, and once given, it cannot be recovered. Many wizards and heroes use false names, or grand titles. This is to protect them from being the target of summoning magics and similar spells. Such spells require knowledge to use, and attempting to summon Allad Allap, or Blood Rose the Sword of Fellwar is going to fail, whereas summoning Albert of Winesap Hill, or Bethla daughter of Belga will work. Once a true name is given, that name is forgotten and destroyed. Family members forget that name, even if it that of their child, spouse, etc. This makes their common used moniker their effective true name. If in the above scenario had Allad Allap given his true name, Albert, he would effectively become Allad Allap for magical purposes.
The sacrifice of true names for power isnt new, and is one of the reasons that many villains have a variety of names attributed to them. One is real, the rest are made up, entertainment, or propaganda. Their real 'effective' name could be completely occluded for their own protection. A gifted magus could use all the true names of people he knew to fuel the powers of the cup, but each use would rob said person of their true name, forcing them to create a new name to exist by. This would be a reflexive action, they would not know their names were lost. They would simply stop being the old name and create a new one. Thusly, if the mage in questioned sacrificed the name of Sollibelle the wench at the tavern to the cup, or any other true name eating magic, Sollibelle would cease to exist, he would gain his power (theft, BTW) and she would adopt a new name, drawn from her own fancy, or something she is commonly called. Sollibelle could become Lovey, or Darling, or Madam Wench of the Golden Ale. Such name robbed people slowly become less of who they were and more of what they are called.
Magi are able to skirt around this, because usually when they are willing to sacrifice their own true name, they are more than willing to discard their squishy sentimental pasts in a ruthless persuit of power, wealth, revenge, etc and said transformation is their desired goal. A non-magic user can give their own name, or they can give the true name's of their children, even if these things are not known. When a woman takes a spouse, the changing of surnames is an imitation of this power.
Alcha's Cup is useless in the hands of a non-magus, or in the hands of a person lacking a True Name. Should she cast her name into the cup, it would be the last time she could use it. Ever.
Allad Allap left, his heart heavy with a loss that had not yet occurred but he knew his destination as sure as an arrow shot true. He now knew why the sages had told him that the giantess' cup was a desperate gambit, why he had been advised to trust in his gods and in his own ability and not seek the secrets of the future.