Evolution by any means!
Xykon explains 'nuances' of power to Vaarsuvius.
You seem have an interest in power, so let me educate you a little while I search for you.
It is sort of the thing I like to do sometimes, especially for learned wizards such as yourself.
Power, it isn't something that you put on or take off like a jacket. It's somethig you just ARE.
If you could lose it by blowing two Will saves, you never really had any power in the first place, see what I'm saying?
Hell, the idiot paladin understands it better then you do. 'cause he got every one of those hit points I burned off of him the hard way: he earned them.
<...>
I used to think spells equaled power, too, back when I was alive. I've learned a lot since then.
You know what equal power?
Power.
Power equal power.
Crazy, huh?
But the type of power? Doesn't matter as much as you'd think.
It turns out, everything is oddly balanced. Weird, but true.
Order of the Stick — Xykon talks about power.