I'm sure the A23 will be a different shape than, say, a AA. This looks promising, for a single:
If you're cutting the strip down, it's going to need less amperage and your batteries will last longer.
A single A23 in each of your knees and each of gauntlets, one A23 in the dress/bodice, and one in the staff ... seems pretty doable. Buy twice as many batteries as you think you need so you can replace them as they wear out.
 I didn't look at the picture good enough, if you're doing the whole "hammer" head of the staff, and not dividing up the LED evenly, then maybe you'll need a different solution for that.