I was already doing a plasma rifle, but the warnings about Balteus convinced me to do some tweaks to optimize the build before going into the End Of Chapter 1 mission. Inverse legs, lightweight arms, the starter head (it's better than the flat-head and it still fit, every other head either made overweight or over-energy). One plasma rifle, one sword, one plasma-mortar, the big volley-missile-mortar, and speed. I might not have been as tough as the full dual Meefcake, but I killed him with style, even finishing with the sword. I honestly couldn't tell if I died or he did in the final explosion, then the dust settled and I had one notch of health left.

Took about 2.5 hours of trying.

Holy shit that was fun. I've played Armored Core games, but only the early ones that didn't have Soulslike bosses like this. That was goddamned amazing.