For that challenge, I used three particular things.
Great Autoheal
Additional Midair Jump
Shulk
Great Autoheal has you constantly healing 5%, which keeps down your percent throughout the climb and fights.
The Additional Midair Jump skill makes many of the boss fights much easier, as it is easier to escape their attacks. Giga Bowser and Ganon in particular are jokes with AMJ.
Shulk's Shield art helped me out a lot in the final fight. Since you can activate it during hitstun, it can make for a good way to get out of attacks without dying.
Another thing that helps is that the Heart Containers given after boss fights will stick around if you decide not to take them. So if you do well on a particular boss, you can wait to pick up the heart later.
Ah, Great Autoheal. I'll try that. I don't need it for the first two phases--there's plenty of healing items to make that bearable. But the actual final fight is a pretty rough endurance, going on for several minutes with all kinds of crazy attacks that you have to dodge, especially in the second half where they get even crazier.
It really is just that second half of the final phase that gets me tripped up. If you pause the game and select "Quit," you can then select "Rematch" and start the final phase over, but that doesn't count for the challenge, even if you beat it without getting KO'd. Because I did do that: get KO'd, quit, hit rematch, then won without getting KO'd, but the challenge was like "Nah."
Great Autoheal might solve that problem. I was using the optimal Dark Samus loadout before, and then I started using Akuma because it does so much damage, but I guess I'll focus more on endurance now. Thanks.
They do get smaller, but smaller and smaller with each new release implies that they're winding down production.
But looking at Smash 4's DLC schedule, it's obvious now that post-launch of Smash 4, Nintendo realized that the Wii U was a sinking ship they couldn't save, and they kept their Smash development staff together to begin work on the next game on their next console. This didn't happen after Melee or Brawl; typically their superteam of developers moves onto other work afterward. Smash 4's DLC, particularly the latter half, was likely a direct result of the decision to begin work on Ultimate so soon, as they could use and reuse their work on characters like Ryu, Cloud, Bayonetta, etc. for the next game.
This is simply my observation, but that sort of perfect storm isn't likely to happen again because, to be blunt, DLC doesn't make the same amount of money that the main game makes, and keeping that staff around to work on new characters over a year post-release when they're not in-house is a huge ask. I seriously doubt Nintendo is keeping them on for another Smash game like they did last time, so DLC would have to sell astronomically well to cause Nintendo to go against the better business decision. Like, a 70+% purchase rate or something ludicrous.
I'd say the recognized the sinking ship by the end of 2015, since that's when Sakurai says that plans for Ultimate were drawn up. I think Nintendo hoped that Smash would save the Wii U in some form, but it didn't do that as well as one might expect (Smash Wii U's lifetime sales have
already been outsold by Ultimate), hence why a year after the game came out Nintendo realized that maybe they could try again so that Smash 4 wasn't going to be Smash's legacy for 6 or more years.
However, apparently getting the licenses for the third-party characters was a struggle, so I wouldn't go as far to say that the DLC for Smash 4 was done with the idea that it would be easily put into the next game. The veteran characters, sure. Sakurai noticed how few characters remained to add back to the roster, and how many people missed the ones that were left out, so he seized the opportunity to retain everyone and bring back the old ones. But the third-party characters are always in the air, depending on the attitudes of the other parties.
Most people agree that it was Square Enix who were difficult to work with for Ultimate, and that Cloud almost didn't come back. If that didn't happen, then there'd be no "EVERYONE IS HERE!" and would've changed the entire nature of the game. EVERYONE IS HERE!*
*except for Cloud would've been really stupid. And I imagine that Sakurai knew that when he first worked with them, based on how there's only two FF7 tracks in Smash 4, so I bet those negotiations to get Cloud back again were a bit harrowing for him, since the entire point of the project hinged on all the characters being there.