Seriously, though, your objection has no real connection to the power. It just has to do with this item being an IoP. Which is fine, but not what I'm talking about at all.
Actually, it has to do with the power being available without the baggage, limits, and responsibilities that restrict its use as part of the Sword of the Cross's powerset.
Incidentally, your comment about baggage is exactly what I'm arguing against. Baggage comes in the form of compels, which are good. If a power is too strong and needs something to balance it, it should cost more. It shouldn't have some kind of narrative drawback. Because narrative drawbacks do not work in this game.
Yes, they do. The inability of Claws to be concealed without a shapeshifting power is a narrative drawback. The fact that a Knight of the Cross can't use his sword for selfish and petty reasons is a narrative drawback. Narrative drawbacks are the fuel for compels.
Compels aren't just be free fate points--there should be significant bite to what the character has to go through after accepting that fate point. A good compel should make the player have to really consider whether they should take it or buy it off. That bite is what I'm referring to as a drawback or restriction--the serious narrative complication that results from the aspect being compelled.
The Sword of the Cross's power is inextricably linked with its narrative role, and the kind of character you can give that power to. You wouldn't have a Han Solo type swinging around Fidelacchius. Or to be more accurate, you couldn't have one of the Swords and keep using it if you're that type of character--either Han Solo loses the sword the first time he tries to use it to get out of his debt to Jabba, or Han Solo develops into the type of character that can wield a Sword of the Cross.
The powers in the book restrict and help define what narrative role a character has. It's not just about the exchange of refresh points for effect.
That's my objection to breaking it down to "3 refresh, a fate point to use": It's taking what, in the fiction, is a rare, extremely powerful artifact that's bound to a set of values and actions, and takes a very specific kind of character to wield, and keeps almost all the power without any of the narrative restriction associated with it.