Give's a bonus to all test
I have a PIXIE his magic rating is 6 he has a power focus of 4 what happens to his concealment test does it give a -6 to perception TEST or a -10 to the TEST?
?
Your pixie isn't the one making that test, someone else is, so the power focus has no effect. It's pretty straightforward, Scawire. When a character with a bonded power focus makes a test (rolls dice) that includes their Magic attribute, they get some extra dice. That's it. That's still a lot, but that's it.
Yes, it worked different in first, second, and third editions, but
so did lots of other stuff. Damage staging changes, initiative rules changed, target numbers changed, damage tracks changed, all kinds of stuff has changed. This is another thing that changed (eight years ago, when fourth edition came out).
Now if you've been using it the other way, and your GM and your fellow players are cool with it -- party on Garth! There's nothing wrong with it as a house rule, if you guys think that magicians need the help. But sitting here and arguing about it isn't going to change the text written on the page.