How did Earthquake hit my Pokemon when it used Fly?

Question

My friend had a flying Raichu from a Japanese event and he used Fly, and Blue's Earthquake hit. Why?

Answer 1

if it was an earthquake from his machamp it is becuase he has the ability no guard which makes all moves hit

Comments

Wait, No Guard Earthquake hits pokemon on the sky(due to Fly, Bounce, or Sky Drop), also Levitate pokemon?

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Not Levitate pokemon, because Levitate makes pokemon immune to ground moves. However, during the first stage of fly most moves miss, (not moves like thunder, hurricane) meaning that No Guard prevents the miss.