Cool Dual Wield Buff Combo

Combo might mislead a little, but if you have the bloodthirsty fiend set, the the gale: doom ability. And the phantom: sword dance. You can activate BOTH buffs at the same time. Now you might say "wow 6 spirit is way too much to commit" but the amount of absolute shredding you do is INSANE. Did I discover something everyone has already known about? Something people dont consider worth it? Tell me what you think!