“It’s probably Matt Mercer’s fault.”
Zelata the witch/druid type was a REH creation from Hour of the Dragon. Conan’s other magic-wielding ally in the story was Hadrathus, high priest of Asura.
It's been a while since I read the stories, but was Hadrathus actually "magic wielding" himself? I seem to remember him giving Conan instructions, or maybe an object, and then Conan experienced the magic himself. But, like I said, it's been a while.
Also, there was Conan's drug-addict sorcerer friend who helped him...I thought his name was Pelas but when I just looked it up didn't get hits. So...again, it's been a long time.