On a nap, you mean, SWITCHED OUT!!?!?!?!?!?! ZOMG! Yeah, T-wave from an above health Nat cripples it, but that doesn't make it a counter, since any slow poke can be switched in to take it. Nat just can't hold up to the power of repeated Hydro Pumps or HP Fighting when switching in, and it needs to be at at least 0% health to take 2 HP Fightings or Hydro Pump
1) ZOMG! KINGDRA MUST'VE GOTTEN SIMPLE! Because apparently it can get 2 DD's on a single switch now. Amazing.
2) Kingdra cannot handle 2 Power Whips, even with 0 Atk EVs. Which means that if Nattorei gets in for free, it kills Kingdra before Kingdra kills it.
3) At least 0% health? That means it's dead lol.
4) Since Kingdra beats Nattorei (if it switches in on a Hydro Pump), then why switch it in? Kingdra cannot set up if you straight-up attack, and will be forced to kill whatever you have in. Then you bring in Nattorei for free and KO with Power Whip. That's certainly better than having Nattorei die and getting swept.