Call me crazy, but isn't the focus will manoeuvre a cheap way to get +2 on many drain resistance tests? It costs 7 BP to get, and you even get another benefit in there to boot (like Ninjitsu's +1 to infiltration tests, which is essentially worth 4BP).

I thought "There must be something that denies it", but I looked and I can't see anything.

It takes a complex action to use. So pretty much not that great in combat. Could be cool in summoning spirits ahead of time.

what is this focus will thing ?

One of the Martial Arts Manuvers from Arsenal.

One question off topic since this one is dead: are spirit's skills capped at 6? If I summon a force 8 spirit, does he have dodge 8 or 6?

No, Spirits are not capped at 6 (or any Force rating), but they do get progressively harder to summon and control the higher that rating is.

Edit: Misread the question ... no, the Spirit's Skills are not capped at 6.

I personally allow Focus Will to apply towards Drain Resistance tests. The only issue is spirits, but then again, spirit drain is a bitch already, so why not?

Reference? Or reasoning.

Cause it says spirits skill level = force, and does not suggest a cap for it