Wind blade cannot mathematically become better than Heavenly Strike in Abyssea.
This is because, While Garuda can Equip Gales for Wind:Major, Ultimate for MAB+50, and w/e last for a good boost. Shiva's "Element;Major" Atma comes with the added bonus of MAB+30. Meaning no matter what combo Garuda is given, Shiva will always have 30 additional MAB on any other avatar. (except Carby, Cause Beyond has light too lul)
But, As for best Atmas for Wind Bland, Even though it will always be inferior to Heavenly Strike, They've already been Suggested :)! you got ~4 options. third atma being either PW or MM(for Refresh).
So if you're going to use Magical Bloodpacts you may as well just merit Heavenly Strike (now, Of course ice isn't good on all mobs, Its nice to have other ones set up for when the time comes. and also a good Physical build)