They were all coming straight for me, and I charged an attack, but it went off in almost less than a second, but there was a burst of fire as well that stretched out to the two fire orbs. So, I did what any sane person would, and I mashed the button.
The Pigmen were hit and knocked back from me by their fire, my blades, and then the orbs, and one of them was killed by a Firebolt. They just kept coming mindlessly, but two more charged attacks and they were all dead.
I tried out the charged attack a few more times and was satisfied with it, but it meant that I had to get pretty close to do damage. It was still really good, but I would have to be careful about ranged enemies. I headed to the next portal and ran in, and burst out onto a mountaintop plateau with two cannon-looking plants.