Bladesworn Transformation is a rather useless ability right now because it prevents all spellcasting and being healed by divine spells. That's why it's almost never used despite being a requirement for anyone who wants Tier 2 of the Angel of Vengeance PrE. The 10 minute cooldown doesn't help either.
Why not make it useful again? Keep the buffs, change the spellcasting prohibition to a spellcasting debuff like the new Tenser's, get rid of the healing penalty, and reduce the cooldown. Just the double cooldown on spells alone is a massive penalty for a healing class, nevermind the other casting penalties. It's not like Favored Souls are in danger of outdamaging pure melee classes in melee combat with the buff on. It's a nice flavoring and compensates for the problem of Warforged having a terrible free capstone spell like Shield rather than free healing or free damage like other Favored Souls.