I'd drop Imp CoA, it's not much of an increase as it takes place before youe +Spell Dam is applied. It's also not the best Curse all the time, CoT on Caster's for example. Pick up Grim Reach. Range is one of our greatest advantages, and using CoEx you can keep that range in Arena's.
I'd also consider dropping 1 point from Shadow mastery for Shadow Embrace, I think Jenova said it does still affect Soul Siphon, so extra 4% on your drains there.