I really want a Garchompite.
The player's Secret Base rank depends on the number of flags they have captured. The Secret Base rank can only be increased by speaking to Aarune at the Secret Base Guild in Fortree City after capturing the required number of flags. The Secret Base rank limits how many special skills Secret Pals can use and influences which items are available for sale at the Secret Base Guild's shops.
Secret Pals are owners of other Secret Bases in the player's game that the player has recruited into their own Secret Base. ... Occasionally, a Secret Pal will also gift the player with a number of flags they have collected (ranging from 1 to 30) the first time the player speaks to them.
You need 1,000 flags to reach Platinum Rank. You collect Flags by visiting other Bases, and taking their Flag when you arrive. You can also get them from Secret Pals, as shown above.
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Hope I helped!
You need 1,000 flags to level up to Platinum.
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hope this helps :)