if weegee side-bs are you are directly in front of him nado is your best option because if you SL it you can trade and die if he misfires
of course you dair him or something if your in the position to do so. master raven specifically said if your in front of him and that is the best option for that situation.
also like i said earlier if you space nado they cant punish you for DI'ing out especially if you no lag land it
DONT tell me im using words i dont understand. I KNOW what i am talking about
if you can ever hit snake with a up-air with him doing nothing you should have hit him with nair instead. upair does 5 damage. nair does 19. HUGE difference. The purpose of spamming up-air is to bait an airdodge or hit him out of an aerial (like if he tries to d-air or b-air you as up-air is much less likely to trade)
you want him to airdodge when he is till above you because you can SL him which kills easiest and puts him in a REALLY bad situation, so spamming up-air can bait this or something you can react to
also nair ends in 31 frames (hitbox out on 3)
snake's airdodge ends in 40 frames (with his invinciblilty starting at 4 and ending at 31)
if you try to nair him and he dodges you still get free d-air (hitbox out on 4)
just make sure to use it only when it will or can hit. its not spammable like up-air is
But you will make less damage with the nado, if they DI out and if they are good at it they will punish you for it (I know that Marth can Up B you out of Nado (when they get hit by it) and MK can Nair you out of it, Olimar can Fair you out, dunno if Luigi can do something like that).
You could also just shield it and then punish it. I dunno, but maybe he got enough lag for a fsmash? Else Dsmash or grab will hit for sure and puts them into a much worse position than tornado.
Sadly human reactions arent 0,0000001 seconds.
A well spaced UAir covers all of his options. If you Nair him single hit he will get a good chance to get back to the floor. He also got a better airspeed than you, which makes it harder to hit him with Nair, espeacally double hit Nair.
You also cant double hit Nair him, else he will just do a bair before you doing the nair and you get hit by it. Single Hit Nair will also just trade most of the time.
A human Snake wont just fall into you. (seriously, only CPUs are that stupid)
And you dont spam UAir, you do well timed jumps + 1 Uair. If he gets hit, repeat, if he dodges, Nair or Dair.