MuAn for increased size

A character of the saga i'm about to start wants to play a Bjornaer Magus with a bear for a Heartbeast and wants to have a spell that increases his size to more than just a +1 as Beast of Outlandish Size. So, what guidelines or extra magnitudes would you recommend? Is there some example in some book?

One magnitude for each additional Size point inscrease.

Note that if the target animal is already above Size +1, you will also need additional magnitude for each 2 Size points (so Size +2/+3 need 1 more magnitude, Size +4/+5 need 2, etc.)

So adding 2 to the Size of a horse (which is Size +2 or +3 depending on type) is level 25 (+1 for initial Size, +1 to increase Size by 2).

Hmm... yeah what Arthur said.. he beat me to posting.

My Initial Post:

There are examples in Hermetic Project... which I dont have at work of course. I think it is +1 Magnitude for each +1 Size change. with a Base of 4 for Changing an Animal (with the first +1 being "Free" at the base 4 level, though you might have additional Target Requirements based on the normal targeting rules on Page 113.

More or less is those the difference of 10 times the size.
That is to +1 like the basic and no extra magnitudes are needed; and those +1 magnitude grant that you can affect one being up +3 categories of Size: +1 - up to +3, +2 up to +6 and so on.

Actually it's +1 magnitude for up to Size +4 and +2 magnitudes for up to Size +7.

For reference see "The Gentle Beast" (ArM5, p.120) and "Shrinking of the Convenient Size" (HP, p.129).

Ok, thanks i didn't see that; but they have sense with the Coprus examples from Hermetic Projects.