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At the Basecamp
Upon arriving here, the game will say it is the start of "Groudon's Heart". Chatot will say you are late, and your team makes some excuses that Chatot doesn't believe. However, he calms down after a while and continues what he is doing. He tells the guild about an amazing treasure hidden beyond the fog, and that was the reason the Wonder Map covered it. Then he orders the members to go and make way to look for the treasure.
After this ends, the game will allow you to proceed onward. Go to the foggier part of the area...but then, what's this? This place seems familiar to you. You seem to remember it as your partner speeds along ahead of you. You're left there, pondering in the fog. After a while, your partner finds a pretty red gem that was lying on the ground. You still stay put, but your partner beckons you forward. According to him/her, the stone is warm. This is worth a lot of money! Wow, we haven't even gone that far and we've found treasure! ...But this does not mean you can slack off. You ponder in the silence again, but follow your partner after he/she tells you to hurry up.
An extremely foggy forest that weakens the power of Electric type moves, so if you have Electric type moves, don't be surprised if it doesn't do much damage. The main type here appears to be Normal, as there are many Normal type Pokémon here, however that doesn't mean there aren't other types. If you've got a Riolu with you, or are a Riolu, then you're at an advantage and a disadvantage, as the Normal types cover for weaknesses by putting Flying types in front of you. It is now much easier to get through as there is no more Bidoof.
Complete this level and you will be taken deeper into the forest, where there is yet more fog.
The Groudon Statue
You enter a place where there is water pouring down all around you, but steamy water. Corphish is there, near an odd statue. You walk forward and talk to him. He says the statue says something in footprint runes, but he can't read it, so your partner steps forward and does. It says something about a stone, being able to lift the fog. While Corphish and your partner are still brooding over what this means, you go and touch the statue. It feels oddly stony. And then...
Dizzy spell. Again.
This time, instead of seeing a vision, you will hear voices, talking to each other. One person says, "Yes, put the stone there! In the heart of Groudon! That will show the sun!"
You think about this for a long time, and then touch it again. It feels more stony than ever. And then...another dizzy spell comes your way. Again.
Again, you don't see anything, but hear something. It's the same voice from before. "Right there, in the heart of Groudon! Do that, and that will lift the fog!"
After a moment of silence you suddenly have an idea--what about the stone your partner found before you came to Foggy Forest. That's it! So you ask your partner for the stone. He/she refuses to give it, but ask what you want it for. After explaining, your partner puts the stone into the heart of Groudon. Immediately it began to grow, and you and your partner as well as Corphish begin to run--
Where's the fog? It's so bright now. And then you remember: "Put the stone in Groudon's heart! That will lift the fog!"
Your partner is exceedingly happy about finding treasure. Corphish leaves you, as he is going to tell the other guild members. However...
Team Skull is back!
They thank you for finding their treasure. Your partner gets annoyed again and fights back. Just when things were really going to get violent, an Apple rolls, with someone screaming after it. It turned out to be Wigglytuff!
Wigglytuff is quite fond of everyone here. He especially likes Team Skull there, as they gave him a Perfect Apple once. He tells Team ____ to go for the treasure. Team Skull gets upset, as the whole point of that was to get the treasure. They try to insist, but Wigglytuff says "We'll let them do the work! Friends! Friends! ♪". Team Skull begins making a new plan.
Despite being hot and fiery, many Bug types live here and could be considered one of the main types, besides Fire. If you have a Fire and Water Pokémon, then you will be the Dream Team here. Just watch out for Volbeat and Illumise's Moonlight. It heals every enemy in the room, which could be really nagging.
After finishing this level, you will be taken into a deeper part. But what's this? There's growling up ahead, making you and your partner clearly frightened.
Upper Steam Cave
It's basically the same as Steam Cave, with the same Pokémon, though a bit higher leveled. The only difference is there is a major decrease of floors, only 7 when there was 14 or 15.
Before the start of battle, it shows the guild rushing to Team ____'s aid. Corphish ask about Groudon to Chatot, who answers. One of the questions was:
Corphish: "What if you were to...battle Groudon?"
Chatot: "Battle? Squawk! Out of the question! That'd be like throwing your life away!"
The Boss is very hard, so make sure you have a number of Reviver Seeds with you to help you if you faint. As well, you should have some Geo Pebbles or Gravelerocks so the Groudon can't stay away. Groudon's Drought ability will cause Sunny weather to appear, which will be an advantage if you're a Fire type but a disadvantage if you're a Water type, despite the type advantage. Sun weakens Water-type moves, so it'd be more reliable to have Grass moves.
When defeated, Groudon disappears...what? That was only a hologram! They walk forward, but a voice stops them. Your partner ask who is talking, but there is no person or Pokémon in sight. Then you will see a glowing orb which becomes Uxie. Uxie then leads your team to the lake.