Suppose a mage with a mean sense of style decides that the stealth adept he caught breaking into his home would be the perfect host vessel for the ally he wanted to conjure. All goes well with the summoning and inhabitation, ending with a flesh form.
The spirit supposedly has access to all the host's memories and abilities, but I don't know how to calculate the magic rating and thus the power points that are available to spend on adept powers. I *think* it should be the same, but I wouldn't bet real money on it.
If the spirit goes free, can the spirit ever increase that number and gain more adept powers? (It got the karma from something or other, source probably isn't important.) Spirits can initiate (though not with the same results as a metahuman wiz), and the normal caps on the metahuman abilities are no longer in force, but I'm thinking that since spirits don't have an actual magic attribute they wouldn't be able to increase in power as an adept. I'd like for the spirit to be able to get more powers, but am not sure it can be supported by the rules.
Essentially, I had a great idea for a recurring bad guy and want to know how much the rules will bend to allow the critter to kick ass to start, and grow so that it can still kick ass once the runners have gotten some skills of their own. Serious munchkinism I'll admit, but I always like to have spare villains around who are just doing their own thing until characters decide to interfere with the fun.