Many Magic players were ready to say goodbye to Chandra, Torch of Defiance after the rotation. Her ultimate ability was a fantastic win condition (deal 5 damage to any target every time you cast a spell) and a favorite of many. But the new Ral planeswalker offers something similar: it deals 4 damage to any target every time you cast an instant or sorcery spell.
Chandra was considered the best planeswalker in Standard. Ral will never take that seat after the introduction of Karn and Teferi, bit it will be very strong in Izzet and Grixis decks. So it won't be a surprise if the price on Ral will grow to at least 15-20 dollars a piece.