Just right out of the gate let me say this: I don’t recommend taking a character from Fabled Lands into the Vulcanverse books. They’re different worlds and you’ll enjoy the experience better if you stick to characters intended for each world. But after all, I would say that because I’m a purist and I always say less is more. I don’t think Professor Challenger inhabits the same London as Sherlock Holmes, nor that the Dollhouse exists in the Buffyverse. As for Doctor Who or Babylon 5 being compatible with Star Trek – ugh, that’s the worst kind of clodhopping fan indulgence. These fictional worlds are crafted to be their own thing, not a great swirling mass of tropes mixing like paint colours till all you’re left with is mucky brown.
Also, the Vulcanverse books start out with your character's childhood in that world and there are callbacks later to your family, even encounters with family members. None of that will make sense if you're playing somebody who has dropped through from a different universe, so transporting a character across is entirely unsupported.
Still, with that warning ringing in your ears, if you really want to throw a Fabled Lands character into the Vulcanverse, here’s how.
Start with abilities. Add up all the contributions from your Fabled Lands abilities (which range from 1-12) to find your scores in the Vulcanverse attributes (which range initially from −1 to +3).
For example, if you have Combat 8 and Scouting 9 in FL then your Vulcanverse Strength score is +1 +1 = +2.
Shards can be converted into “pyrs”, which are what coins are called in the cryptic world of the Vulcanverse. However, you can only take a maximum of 300 Shards as “pyrs” when you travel between the universes.
Rank in Fabled Lands translates to Glory:
Lastly, you can translate ability-boosting items into attribute-boosting items as follows:
Laurel wreath any +1 or +2 Charisma-boosting item from FL
Golden lyre any +3 or better Charisma-boosting item from FL
Recurve bow any +1 or +2 Scouting- or Thievery-boosting item from FL
Winged sandals any +3 or better Scouting- or Thievery-boosting item from FL
Hornbook any +1 or +2 Magic- or Sanctity-boosting item from FL
Abacus any +3 or better Magic- or Sanctity-boosting item from FL
Hardwood club any FL weapon with a Combat bonus of +1 to +3
Iron spear any FL weapon with a Combat bonus of +4 or more
You can convert one such item per attribute – so, for instance, even if you own a dozen +6 weapons in Fabled Lands you can only go across to the Vulcanverse with one iron spear.
God? The FL gods are unknown in the Vulcanverse. The Greek gods mean nothing to somebody who has travelled between the planes from Harkuna. So if you're doing this you will start out with no god to call on.
And where would you start? Try 222 in any of the first four Vulcanverse books. And don't say I didn't warn you.