How do you get into the 8th gym in Pokemon emerald when Archie is obstacle door?

You can't get into the 8th gym (Sootopolis City) with Archie blocking the door. You need to defeat him first. Here's how:

1. Go to the Seafloor Cavern: Archie is blocking the entrance to this cave, which is necessary for progressing the story.

2. Talk to Steven: Inside the cave, you'll find Steven, who will ask you for help.

3. Team Aqua's Plan: Steven reveals Team Aqua's plan to awaken Groudon and change the world into a landmass.

4. Go to the Ancient Tomb: Steven leads you to the Ancient Tomb, where Groudon is being held captive.

5. Defeat Team Aqua: Inside the tomb, you'll have to battle Team Aqua members and eventually face Archie himself.

6. Confront Archie: After defeating Archie and his crew, you'll stop their attempt to awaken Groudon.

7. Return to Sootopolis: With Archie defeated, you can finally return to Sootopolis City and challenge the gym leader, Wallace.

Remember, you cannot bypass Archie by any other means. Defeating him is crucial for the story progression and for accessing the 8th gym.