After a few days that the game got released, we now know some of the toughest Challenges in Super Smash Bros. for Wii U are. And if you'd like to be prepared on how to react accordingly, feel free to watch this thread.
There's one that involve clearing 9.0 Difficulty in Classic Mode without losing a single life. Aaaaannnndd you can't use a golden hammer on this challenge! If you think this'll be a piece of cake, the AI in this game's CPU is even more brutal than what the 3DS version and Brawl did because of their tendency of doing wombo combos. It's best to avoid 8 Player battles as often as you can, since that's where the CPUs become your worst threat.
Since there's apparently no restriction on the use of customized characters, I believe it might be wise to use a character with a lot of defense and significantly buff the Defensive stat to help you prevent from racking too much damage in a quick succession. And perhaps more Offensive stat if you want to finish the fights a bit quicker.
There is another challenge that once again involve clearing 9.0 Difficulty in Classic Mode without any customization whatsoever, but you can use a golden hammer on it (well, I think so) to spare your sanity. This time, we don't ask you to not lose a single life, so you can afford to lose one life in any fight before the one against Master Hand and Crazy Hand. In SSB4, you always start with two lives on each fight regardless on how many you had from the previous match. If you don't ever lose a life on your playthrough while completing this task, the challenge I mentioned earlier will be completed as well.
If you're undertaking these challenges, I'd wish you a good luck. I never tried them yet, but that's what I found in the Internet and analyzed it a bit. By the way, discuss what are your most difficult Challenges you've undertaken so far, along with strategies on how to accomplish each task.
There's one that involve clearing 9.0 Difficulty in Classic Mode without losing a single life. Aaaaannnndd you can't use a golden hammer on this challenge! If you think this'll be a piece of cake, the AI in this game's CPU is even more brutal than what the 3DS version and Brawl did because of their tendency of doing wombo combos. It's best to avoid 8 Player battles as often as you can, since that's where the CPUs become your worst threat.
Since there's apparently no restriction on the use of customized characters, I believe it might be wise to use a character with a lot of defense and significantly buff the Defensive stat to help you prevent from racking too much damage in a quick succession. And perhaps more Offensive stat if you want to finish the fights a bit quicker.
There is another challenge that once again involve clearing 9.0 Difficulty in Classic Mode without any customization whatsoever, but you can use a golden hammer on it (well, I think so) to spare your sanity. This time, we don't ask you to not lose a single life, so you can afford to lose one life in any fight before the one against Master Hand and Crazy Hand. In SSB4, you always start with two lives on each fight regardless on how many you had from the previous match. If you don't ever lose a life on your playthrough while completing this task, the challenge I mentioned earlier will be completed as well.
If you're undertaking these challenges, I'd wish you a good luck. I never tried them yet, but that's what I found in the Internet and analyzed it a bit. By the way, discuss what are your most difficult Challenges you've undertaken so far, along with strategies on how to accomplish each task.