Lets say you have 2 blastoises.you taught 1 hydro cannon.what about the other blastoise?
1.well,get a link cable and another firered or leafgreen catridge with the adventure 100% finished BUT NOT WITH THE STARTER TAUGHT THE ELEMANTAL ATTACK!2.Then,bring both people into a pokemon center,then go to the top floor of the pokemon center,head right till the end,then go up till you see a lady.3.Connect the link cable before you talk to the lady straight of you after you look up.then,talk to the lady,then select trade center.after you both get into the room,then trade your pokemon blastoise with a pokemon the other guy doesn’t want.4.then,go out of the room.make the other guy go to 2 island,then go up the hill till you see a house.5.then talk to that girl in the house(make sure the blastoise that the other guy has is in the first section in the ‘pokemon’ section when you press start before you talk to the girl).6.then,tell the girl to teach the new blastoise hydro cannon.7.then,control the trainers to go to any pokemon centre.8.then,replay step 2 but now just trade back the new b