
u/Debonaire_Death

I know I'm late to the AC6 party but it was so much fun going through this game. It has a fascinating proclivity to seem impossible one moment and doable the next, over and over again.
The last boss was definitely the pinnacle of this concept--it felt SO HARD to get through phase 3. I honestly had no idea what to do for awhile. It was like I needed one build for phases 1 and 2 and another for 3, and I couldn't square it. I tried fast builds designed for burst damage, and heavy builds designed for huge kill shots, and nothing seemed to give me a chance in the final phase while allowing me to handle the first two phases easily.
In the end, I had the sense to assume I should be trying to utilize as many late-game parts as possible, especially coral weapons, since they bypass damage resistance. For awhile I was doing this same build but with a Coral rifle in the right hand, with the hope of making use of its charge shots, but it just complicated the gameplay too much and the bosses in the final fight are too mobile and recover from stagger too fast for the charge shot to actually land serious damage with any consistency.
Having some no-nonsense normal missiles was also a godsend for keeping the attitude pressure in the different phases, and the redshifts are so choice. Going double with those simplified my gameplay and let me focus on learning the moves in the final fight. I wasn't even using charged Coral missiles in the last phase--it just wasn't worth the brain-power.
I saw people saying to pick off the Mind Alpha models in the beginning phase, but I just equipped the VE-21B and pressured Iguazu from long/medium range, never had to kill one of the silly fuckers.
Another key change in my strategy was to treat the last phase more like a bullfighter than a gladiator. I had to recognize that he was faster and more mobile than me but a lot of his attacks had momentum that I could blow past by QBing into him,so that he's just slashing at the air behind me while I can come around with a charge shot. That, and getting down the timing for charged Redshift shots so that I could stagger him, really chipped down that last half of his health.
I'd been getting mopped up like grime on the floor one sortie and, the next, I had him down to 20% health and still had two repair kits and another pulse shield. It was crazy how quickly things tilted in my favor with the right strategy and tactics. I went from having never managed to stagger in phase 3 to killing him outright in one try. I adore that about Fromsoft games!
Now it's on to multiplayer, I suppose! I'm hoping there is still an active player base. It's such a fun game, I have hope that people have held out and still enjoy it.