Funi is a special creature living in a pot asking you for specific items. It cannot be sent to the Dimengeon, thus, you'll always fight it in a regular encounter. The first item it asks for determines what gemstone it is making. After you successfully fulfilled its requirements, it'll give the gemstone.

Personally, I don't really think farming Funi is necessary in this game. Plus to get to the XL gemstone, you'll probably need to max out your Growth Map before you even be able to deliver enough damage to fulfill the requirement.

Here is a reference list and their locations:

For the "One big shot" to get Ruby XL and Emerald XL, first:

• apply "Defense Down" on the Funi
• then buff "Attack Up" on Cheryl
• and use her combo "Concentrate" + "Charge" + "Charge" + "Blizzard Strike" to deal enough damage.

For the "Damage" to get Pearl XL and Opal XL, first you'll have to pre-buff your damage dealers before you get to the XL tier:

• Bring all your damage dealers: Leo, Cheryl, Tan, Zinikr, and Prickle. They all have "Charge" and "Desperation" skills
• Leo: "Concentrate" + "Desperation"
• Tan: "Mystery Potion" + "Desperation"
• Cheryl and Zinikr: "Concentrate" + "Charge" + "Charge"
• Prickle: "Charge" + "Charge"
• Ez helps with buffs "Quick All" and "Attack Up"
• Once your setup is ready, bring Kina, Valrika, and Ez to fulfill M and L requirements.
• Once you get to the XL where you have to keep dealing damages, swap in all damage dealers and give it everything you got.

Note: You may want to do the same with "Elemental Damage" requirement.

For the "Number of Hits", bring Leo, Valrika, and Prickle and use "Samidare +2", "Arrow Rain +2", and "Frenzy +2" respectively to reach a certain of hits to fulfill the requirement.

You'll always start with M tier. After you completed the requirements for M, it'll ask if you want "something even more impressive". If you choose "Yes", it'll start making L tier, then XL.

You'll always start with M tier. After you completed the requirements for M, it'll ask if you want "something even more impressive". If you choose "Yes", it'll start making L tier.