Male protagonist with prosthetic arm, vampire girlfriend, female barbarian under a curse — late 80s–early 90s?

Question

The book is set in a medieval world and features a male protagonist named Jonah, who has a magical prosthetic arm. There is also a female vampire named Emma, who is his love interest, and a barbarian woman named Charyn, who is under a curse and turning to stone.

Not 100% on names, as I put the basic details through ChatGPT, and this is what it came up with, but it only gave me the right characters and synopsis but wouldn't give me the right book name.

The plot involved a prophecy about Jonah and his arm. Though in the story, it wasn't meant to be him. The prophecy involved a boy missing an arm who would be given the prosthetic by some priests, so his father cut off his arm to make it happen.

There is also a brother-sister villain duo who caused the curse on Charyn and are trying to stop Jonah from fulfilling the prophecy. In the meantime, the duo is kidnapping women to breed hybrid lizardmen and humans.

Parts of the plot I remember: it opens with the trio on a transport ship, the crew trying to rob them and getting killed, the captain being shot in the throat by her own poison dart, the vampire going to feed on the wound, but Charyn told her to stop its poison.

At some point, the villain duo sends a mercenary to hunt them and wipe his brain so he's mindlessly obedient, and he travels using a balloon that flies using methane.

After finding a ruined city, the heroes later arrive on a beach and get ambushed by some killer eels. Emma runs in and strips off her clothes because the eels die if they touch her undead skin.

i remember the cover of the book at the time, had Jonah kneeling and trying to grab some magic staff that was glowing and burning his hands, emma was nearby shielding her face from the bight light, and Charyn was on his other side just standing there

Answer 1

This is the Arcana series by Morgan Llewelyn and Michael Scott. The cover you remember is from the second book Silverlight.

ChatGPT has hallucinated the names as the boy is called Caeled. Also his arm is not cut off by his father to fulfil a prophecy. He loses his arm when his hand is bitten by a beast called a Madra Allta:

"You have a choice, boy", said Armadiel in a matter-of-fact voice. "The Madra Allta bit you. I don’t need to tell you what that means, do I? The corrupting poison is your hand. I think I’ve prevented it from spreading in your arm, but I can’t be certain." He looked at the mangled hand, then back into Caeled's horrified eyes.

"Unless we do something, you will become one of the Madra Allta. The only sure remedy is amputation." He touched the boy's forearm just below the elbow. "Here I think, to be safe."

The woman turning to stone is Gwynne:

Wordlessly, the woman dropped her cloak to the ground, then undid the ties of her tunic and pulled it over her head. Naked, she turned slowly, letting them look. Much of her body appeared to be petrified. Cracked granite spread from between her shoulders and down along her spine, tracing her ribs around to the front of her torso where a gritty grayness covered most of one breast, leaving a portion of the nipple pink. The adjacent arm was as gray as the breast. Her belly and upper thighs looked like solid stone.

"Nine days ago I was harvesting with my husband and five children in Brethany," she told her horrified audience. Her eyes glittered in their granitic mask but did not weep. Could not weep. Stiffening facial muscles had closed the tear ducts. "Something fell upon us out of nowhere, a gray void that consumed my four sons and snatched my baby daughter off my back. I think it took my husband too."

The vampire is Sioraf:

Her face was like a pale oval of moonlight. Her lips were very red. Caeled could not tear his eyes away.

"I smelled blood on you," Sioraf stated flatly.

Caeled knew he had washed thoroughly, not once but several times, since his last encounter with the Bred. Perhaps there was still blood on the Stone Warrior, though. It might have seeped into the fissures in her skin. How could this young woman detect anything so subtle? The safest he, he recalled reading, was the one nearest the truth.

"We were attacked by beasts in the mountains, some sort of huge lizard creatures. But how could you tell? You must have a fine sense of smell."

Sioraf's red lips curved into a smile of incredible sweetness that made Caeled's heart lurch. Then the smile widened, and he saw her needlelike incisors.

"I am a vampir," she said simply.

The twins are Sarel and Lares, and you say they have found a way to control the voids:

Sarel cupped her hands around her brother's gaunt face and looked into his eyes, seeing herself mirrored in them. "Think of it, Lares, think of it. We have proved that the Voids can be controlled ... and if we control the Voids we control the world!"