One of Isis’ most powerful epithets is “Great of Magic,” which you may also see translated as Great One of Magic, Great Sorceress, or Great Enchantress. In Egyptian, it is Weret Hekau or Werethekau. (“Wer” is “great” and “et” is the feminine ending. “Hekau” is the plural of “magic,” so you could also translate it as Great of Magics.)
Isis is not the only Goddess Who is called Great of Magic. Many of the Great Goddesses bear that epithet, too: Hathor, Sakhmet, Mut, Wadjet, among others. Gods are also Great of Magic, notably Set in the Pyramid Texts.