Defeat the gymleader.
Open the door and challenge the gym leader.
you dive to get to sootopolis which is in the south east from mosdeep then fight groudon then you can challenge the gym leader and get your 8th gym badge. then u challenge the elite 4.
It is in Ecrutuk city the leader is morty who uses ghost type Pokemon
you build up your Pokemon higher than the gym leaders and the you kill the gym leaders Pokemon and as they all faint you will get a badge and you have to move on to nuger 4 gym leader
beat the 1st 4 gym leaders and get to the next city
There is only 8 badges. Gym 1-8 Elite 1-4 The Champion
I'm pretty sure you go back to Petalburg to battle Norman for the 5th gym badge.
It's in the amusement park
Well, it really depends on the level, Have the following badge to have the certain obedience lv. Eg if u have a level 22 but only 1 badge it will not obey u, but it u have 2nd badge it will obey u UNTIL LV 30! unless u have 4 th gym badge) Get it? 20-30 2nd Gym badge 30-50 4th Gym Badge 50-70 7th Gym badge (some games 6 badges) 1-100 Last badge (have every badge) Hope i helped.
you have to get the 4th gym badge hm05 defog(first person to the right in the great marsh) and than in addition have 4 total gym badges good luck and have fun=-)
really there is no simple explination except use dark or ghost Pokemon
Go to Lavaridge city