Thanks. Like I said, my game's got someone who wants to do the lightsaber thing, so I'm gonna playtest it there and see how it goes.
If the character's fighting concept is revolving around the lightsaber, may I propose a different approach?
Give the character channeling (fire) and claws. Since you probably want more than weapon:2 for you sword of fire, let's borrow from Incite Emotion's "Potent Emotion" and make it weapon:4 for 2 points of refresh.
Now you attach a custom power to the double claw power, refunding you 1 refresh, so you end up with a cost of -3 refresh for the whole package again. The custom power is basically human form, but you need to cast a spell to activate the powers that are attached to it. If Sanctaphrax is stumbling in here again, he can probably post a link to the entry in the custom powers list, I was unable to find it.
So what will happen is, the character casts the "Sword of Flames" maneuver on himself and tags it to activate the reworded claws power. From then on, he can use the Sword of flames like any other weapon, it will only go away if he wills it away (or maybe someone counters the spell). That way you won't have to deal with additional casting stress, duration and all that would be involved if you try to tailor it around the actual magic skills.
Darn the vagueness of the RAW. I'm starting to wonder if they're doing this on purpose...
I believe they do. It is the systems greatest strength and greatest weakness at the same time. Often enough you can create the same effect in a lot of different ways, and what seems to be the direct approach at first doesn't always have to be the best.