Time Spiral, Rare. Jaya Ballard has a long and interesting history in the MTG universe. As a character, she originated in Ice Age, which came out in 1995. In the event you were wondering, a task mage is a term for a maverick wizard who works as a sort of hired gun. There were auramancer task mages, cryptomancer task mages and more. Jaya…well, Jaya burned things. A lot. With gusto. She was so famous for it that flavor text quoting her has been featured on 7 different burn spells.
Jaya is also what I like to think of as “The Proto-Walker”. In the story, Jaya is indeed a Planeswalker. The thing is, when they finally printed her as a card, Planeswalkers as a card type didn’t exist yet. But if you look at her design as a creature, it’s fairly obvious that she was the basis for future Planeswalkers. Three activated abilities, each on par with a spell (in fact her 3 abilities were the spells Red Elemental Blast, Incinerate, and Inferno. Two of which featured quotes of her’s in their flavor text).
I think from a design standpoint, the fact that she was so fragile is why they created the loyalty counters mechanic with the Planeswalker card type. Your nigh-deific card should not be able to be killed off with a simple Shock.