For Myth, I would not recommend having 7 in Spirit's Anger. It overrides other people's buffs like magic defense, so you'd either have to back off on using it a lot, or risk using it and having people not being able to use their buffs. Quite often Siegs, even Kriegs, rely on their magic defense at CoC and M2 and may die if they don't realize they can't use their buff over yours. 4 would allow them to override your buff.
Do you plan to solo? If so, Fierce Wind/Arrow of Wind are nice for extra pushes.
Other than that, everything seems good with the build.