Have you checked is it better for you to run Cybele over Amaterasu? Cybele would do notably more damage than Amaterasu, but would also lower your Def debuff by 5%.

Sol is always good to have, but keep in mind that the flipside of Wind is Water, so working on your Water team might also be a good idea (Cthulhu/SSR Nike/Water Raphael being the trinity there, though Ryu-Oh should also be mentioned for having three good debuffs). Otherwise, you might struggle during Fire events. Not that we'll have any of those for the next six months.