I work in a garage that has no electricity so everything that needs electricity currently has to use battery power - my lights, my power tools, my music...! I have been lucky enough to gather together a few Makita power tools - it seems to make sense to stick to one brand and platform when it comes to power tools so I'm on Makita LXT and I have several batteries meaning that I can buy 'body only' tools.
I have; a couple of LED work lamps; a combi-drill; a jig saw; an angle grinder; and...a die grinder. Whilst all are very useful and are regularly used, I have been most surprised and pleased at just how much the die grinder can do. I use a set of rotary burrs and a set of grinding stones.
The rotary burrs have proven to be great for rough shaping and partially skeletonising the blade blanks - I then use the stones for smoothing things off a bit. A word of caution...the die grinder with rotary burrs is a pretty aggressive tool capable of removing a lot of steel and biting chunks out if you don't keep a very firm grip and steady hand on it. Suffice it to say that glasses / goggles and a face shield are a must.