Alright magnezone, jirachi, heatproof brozongs dont take the earthquake damage directly like a Pokemon standing on land would. Rather, they take damage from the sound waves that are produced upon an earthquake. Seismic waves(which are vibrations that travel through the earth carrying the energy released during earthquakes) cause vibration within the interior of earth and the vibartion eventually leads up outside the surface causing the sound waves to travel thourgh the air
Also, magnezone uses magnetic currents to move around and float, and during earthquakes theyre all get screwed up because of the sound waves thus causing him to have a 4x ground weakness and that jirachi doesnt because he doesnt use magnetic currents to float he has the psychic powers
^What I'm trying to state above is that magnezone has 2 things that hurts him and jirachi only has 1 thing that hurts him so thats why magnezone has 4x and jirachi is 2x weak
So magnezone is 4x weak because(yes I know the typing determines the weakness) 1)sound waves from earthquakes hitting him, 2)magnetic currents gets messed up
Jirachi is only 2x weak because 1)sound waves from earthquakes hitting him
