Order should be Cú Chulainn, Titania, flex slot, and Aether. If you're fighting TRag I'd probably use Gaia whereas for solo content Hastur would be more useful for her debuff. You'll typically be using Titania to buff Aether either with BG gain or DATA up. Aether usually goes last since you'll be using her burst damage up ability which costs 10 BG every turn. As for the soul, definitely Shingen. Hercules is too slow for wind especially if you want to use Provisional Forest.