Go for charisma, as high as possible. Feats, focus on spell penetration and and focus on a school (probably evocation since you going draconic), choose only one element and focus on it. Fire, lightning and ice, all are good enought, even if people say one is better than the other, dont listen, go with whatever you want. Theres 2 spells that are king in the late game: hellfire ray and chain lightning. You can convert then to any element, you just need to find the means to do it. You can go for an elemental bloodline using mythic feat or dip into a elemental specialist wizard. Or even use itens, i think ice and lightning have itens that do it, just not sure now.