3d6

[5e] Astral Elf or Eladrin would be perfect to have all the teleportation the Ciri does, as their Fey Step or Astral Step will allow a lot of trivial, non-spellcasting 30 foot teleportations. And bonus: Ciri is part elf!

Additionally Relentless Hex will allow the character to teleport directly to their hexed opponent.

Medium armor is there to represent aesthetics as well. Additionally, Invocations can be learned for Planeshift, teleport, and other flavorful selections to represent Ciri's ability to traverse different worlds entirely. Additionally, turn by turn a hexblade can get by without using magical blasts, just using their sword and various things that boost the damage output.

And while the OneD&D UA for Warlock doesn't have the hexblade class yet, I feel like it would more easily represent Ciri's casual use of magic as well as the depths of magical ability she can sometimes call on.

Just going to say she's a dual-class sorcerer and whatever flavor of melee a Witcher is, looks a lot like a ranger given the leather armor, skills in tracking and woodcraft, lore, etc.

Don't think the magic system translates well.

It's been a while but doesn't Ciri just gave that teleport ability and is a sword user? I'd probably go fighter and maybe pick up zephyr strike and misty step with some feats