MG Excelsus No Damage (Revengeance difficulty, S rank) 

Would love to get an S rank kill that isn't segmented and doesn't need restarts, but I just wasn't able to do it. Might try it again later, now as far as this run is concerned I'm going to go back and do the fights I did no damage but did not get S rank(GRAD and Sundowner). Also was not sure whether or not to have this fight and Armstrong be separate, or have it all combined into one big kill. Armstrong will be uploaded somewhere in a few days.
The thing that makes this fight difficult is the section with the lasers and the Gekko units, I had some really stupid things happen sometimes(Gekko surviving a laser and doing its charge QTE, and then while in the QTE a laser going through and killing me but not the Gekko). I probably just wasn't standing in the right spots, but I found that part to be inconsistent. This might be one of the first fights I used boss weapons for, I think Sundowner's Pincer Blades have a lot of good uses in this fight. The charge attacks can do some work on Excelsus's limbs, and if you can line it up right you can use the aerial attack and land all of it on the laser limb things before the Gekkos arrive and have the boss down to like 15-19% HP. If you were to do this all in one go, Mistral's weapon and its one spinning combo and/or maybe ripper mode + blade mode would probably be the right choice for building up 50+ hits while the boss is down after the first QTE. On the first attempt it appears to have moderately less downtime, so the combo I did in this video probably doesn't work on the first try.
Over the last day or two I spent most of my free time working on better strategies for this fight and Armstrong, and I've managed to get some pretty good fights. The previous kill on this boss took about 5:30, worked on the general execution of this stuff along with figuring out a thing or two to do with the Pincer Blades, shaved off a decent amount of time. Worked on a strategy for Armstrong that allowed me to clear a whole minute faster than the last kill I had, and so it all turned out nicely I think.