How do you complete Robin's flurry attack challenge?

There is a challenge that reads:

As Robin, use a flurry attack to KO a Lv. 9 CPU in a 2-player battle. This must be done within 3 minutes, with spirits off, and without handicaps.

I've tried for at least an hour to open this challenge, but nothing I do seems to be working. I assume by flurry attack they mean Robin's rapid jab attack, where he uses his wind tome. I've tried many things:

• KO the enemy on a stage with walk-off blast lines, such as the Boxing Ring.
• KO the enemy using the lava in The Great Cave Offensive.
• KO the enemy the regular way on a normal stage, KOing them when they have a high enough percentage.

None of it worked and I'm sure the match was over within 3 minutes. What am I doing wrong?

Solution 1:

You must fight a timed battle of length < 3 minutes

Looking at "walkthrough videos" (that really aren't too helpful) both here and here, it seems they've both used rule sets that set the match time to be less than 3 minutes. This is confirmed to be necessary in the comments:

Just so everyone knows, I've tried this multiple times and it didn't work. I changed the time to 2:30 instead of 3:00 and it instantly worked. Give it a go if you've been having the same issue.

- MiLo ChaelPez

So even 3 minute matches are too much!

In addition to this, I'd suggest fighting against a Jigglypuff, as Puff is very light and so will be launched further from your attacks and be killed sooner.

From another comment, it sounds like you can even get away with turning the launch rate up to 2.0x and still complete the challenge:

what i did was i choose jigglypuff as the cpu and set the launch rate to 2.0, then i went to Dreamland and beat it there

- DoggoTron

If you're having trouble actually doing the Rapid Jab, we actually have a question on just that (for this character too!) here.