Before that, we should actually write a guide for the final boss first.
I had planned to do it once I finished my synergy run, since I would have had to beat it without using too many characters that are considered top tier. This way, I could have objective views on the final boss and write a proper guide. That, and the fact that I was already over leveled, and didn't want to go through the trouble of fiddling with the level unification and Voile to get a proper feel for final boss.
I think it should be a priority over post game content.
What I forgot to add to this was, "Since the new patch, I've been too busy going through the post game content to finish my synergy run."
The floor function is just rounding to the lowest integer.
Also I see your point on the final boss. I can note down the phases and such, but as for actual strategy I think I'd leave that for someone who is better at... strategizing. I mean, for Hard Mode I basically had Byakuren, Suika, and Remilia plug away at it with Leaning Iron Mountain until it died.
I'm not exactly much better, at least for this particular fight. I tend to just have Kaguya spam Swallow's Cowrie Shell. Everyone else is there to support her, either through buffing, debuffing the boss, healing or inflicting Poison / Heavy.
There obviously should be some strategy involved, seeing as the boss uses World Shaking Military Rule, as well as Great Calamity and Great Ruin at specific HP thresholds, but I couldn't be bothered to mess around with my main file to actually develop one.
And aside from me whining about how lazy I am, I've also noticed that the final boss has had some of its behavior patterns changed since 1.151 so even if I really wanted to, I'd still have to figure out whats different.