i guess its time for me to finally contribute to the DK boards after all everyone here has helped me get so far, (AUS DK).. one of the best currently. ok here we go.
Nado-
This move is ********, if MK uses this move correctly its very hard for DK to do anything about it, especially when pressured off the edge.
Our arsenal:
Ftilt
Utilt
Uair
Dsmash
DK Punch
Bair
Shield.
OK. Lets start from ideal move to when your stuck in a bad situation and have limited options.
provided you can space using the stage to move forward and backward to space, Ftilt, Utilt, DK punch and Dsmash are probably your best ways of knocking MK out of nado.
#1 Option is Ftilt, aimed upwards like ripple posted earlier, will knock MK out twice, then it will be too stale and you'll get punished. remember to space it correctly, you have to be sure that MK is going to run into it.
#2 Utilt, again as rip mentioned this will only work once, and the range is a lot harder to space, this will take some practice.
#3 Dsmash and DK punch are probably about equal here, Dsmash comes out just fast enough with just enough range to knock him out provided you get DK's fist the range it needs. DK punch will hit straight through a nado close to the ground, but remember only the grounded version of DK punch will stand upto nado. an aerial version wont work, you will only be sucked in and lose your stocked punch.
#4 Bair... hey. if you've ever played DK you must know how good this move is, how can it not beat nado? well with the right spacing you can beat nado with bair. problem is the spacing is extremely hard in competitive play, id recommend not trying to use bair as it'll get you more punished than not.
#5 Shield. so your stuck in shield, because MK is using nado in your face. what can you do? first things first. angle your shield up, to prevent pokes (MK needs to hit your shield, move away and then come back in without you angling your shield for him to poke.). ok so MK lands next to you or moves away and lands, after doing a Nado MK will undergo 29 frames of ending lag, although if they end in the air, they can eat up 10 frames, meaning that when they hit the ground, you actually only have 19 frames in which to act (i'm not sure on how much shield lag you undergo could someone help me out?).
I myself usually punish nado using Grab/Dtilt/Ftilt out of shield (if MK is close enough) and Down-B if he moves away. Spotdodge at the end of nado to avoid shieldstun if you can memorise the timing, but shield is probably safer.
#6 your about to get hit! quick SDI up and punish using a fast falled uair, i've heard people say this works but Ive never been able to make it happen? i'll see what others think. you'd have to SDI during the first hit of nado as the rest dont have enough knockback.
try not to get too mad, there have been times where MK goes unpunished after ending nado next to me and continues his barrage with a downsmash. if you are worried about that, just resort to using DK's frame 6 jab or frame 6 Utilt (provided MKs close enough)
So thats everything i can help you guys with in regard to Nado..
DO NOT APPROACH. i cant stress this enough, MK has better moves, he has the frame advantage in almost every aspect, being DK what you want to do is control the middle of the stage, push MK off the edge. but don't approach him when hes air camping, this matchup will require all your mindgames ^^.
Remember that you are scary, you are the stronger Kong. DK is a force to be reckoned with, when your moves connect, your opponent will cringe with virtual pain. MK will be afraid, use this to your advantage.
when you're off the ledge you may as well drop your controller. MK can shuttle loop over and over until he gets the KO, and there's nothing we can do as if DK air dodges he will plummet to his death.
STAGES:
Neutral - Battlefield, Smashville.
Ban - Frigate, Brinstar, Rainbow Cruise (probably in that order)
Counterpick.. Jungle Japes (banned), Yoshi's Island (they will ban), Luigis Mansion (banned), PS1 / PS2. PS2 is probably better as DK can abuse the low gravity a lot better than MK. PS1 and PS2 have good platforms to abuse with DK's supercopter and it increases his getback options using autocancelled spinningkong
Final Destination is ok because of the size, you can space with a comfort zone
Delfino / Halberd have the option to shark, but MK uses this a lot better than DK.
Yoshi's is probably best, followed by Jungle Japes (off ledge options yay..)
SUMMARY
Do not approach
When spacing aim to take 2 steps forward, 1 step back, slowly push MK towards the edge.
angle shield up against nado
Do not approach
counterpick whatever you feel most comfortable on, there's no point experimenting with stages against MK
Sorry this was such a large wall of text, but I hope it helps a fellow kong..