Once you reach level 50, talk with Zena in the market (279, 543). She will tell you how Arthurian in the Elven City (128, 163) has worked out a way to enable you to summon three Eudemons. She can teleport you to Arthurian.
Talk to Arthurian and increase your relationship points with him by finishing the quests he gives you. When the relationship points between you and Arthurian have reached 1000, he will hold a '3 Eudemon Ceremony' for you.
There are four kinds of quests that you may receive. They are a random mixture of 10 'sending' quests, 10 'killing' quests, 10 'purchasing' quests, and 10 'collection' quests. Finishing each small quest will increase your relationship points by 10. When your points have reached 200 and 500 points, he will ask you to give him a 15-star Atk-def Eudemon. (Both Warrior Atk-def and Mage Atk-def are ok.) Then your relationship points will increase by 200 points each time.
1. Bring a letter to the carpenter Raven in Windmill Town (670,542) about how to make his windmill work again.
2. Ask Armstrong in Cronus (280,386) about the ingredients in Magic Eye Potion.
3. Find Eagle Eye Nelo in Misty Marsh (479,645) and bring his report about the geography and biology of Misty Marsh back.
4. Find Ida in Misty Marsh (270,426) and bring him good news--he is to be a father!
5. Tell Claude in GobiDesert (382,032) that he is wanted by the royalties.
6. Bring a message to Raul in Gobi Desert (470,713). It's said the message is from a ghost.
7. Tell Chic in Icy land (295,295) that the Lion Gate is around the northeast part of the land.
8. Tell Gaspar on the Island(1037,1206) to bring Arthurian's magic pigeon during his sailing.
9. Tell Adam in Volcano(432,540) that the volcano is to erupt and ask him to come back as soon as possible.
10. Ask Walter in DarkMarsh (272,531) to send the Soil Herb Root to Arthurian as soon as possible.
1. Kill 100 Green Devils outside of Elven City.
2. Kill 100 Banshees around the Stele Pool.
3. Kill 100 Satyrs outside of Elven City.
4. Kill 100 Eye Balls outside of Elven City.
5. Kill 100 Ogres outside of Elven City.
6. Kill 50 Big Fangs outside of Gobi Desert City.
7. Kill 50 Wyverns outside of Gobi Desert City.
8. Kill 50 Golems in the north of the Gobi Desert.
9. Kill 50 Lizards in the Gobi Desert.
10. Kill 50 GhostKnights in the southwest of the Gobi Desert.
1. an Apocalypse I from the grocery store in Cronus.
2. an Apocalypse II from the Elven City's grocery store.
3. an Apocalypse III from the grocery store in the Gobi Desert.
4. a Black Hat from the armor store in Elven City.
5. a Blue Crest Helmet from the armor store in Elven City.
6. a Kennan Armor from the armor store in Elevn City.
7. a Tulwar from the armor store in Cronus.
8. a Violet Hat from the armor store in Cronus.
9. a Hand Blade from the armor store in Gobi Desert City.
10. a Winged Helmet from the armor store in Gobi Desert City.
1. Kill Green Devils outside of Elven City until you have Collected 10 Gnomes Totems from them.
2. Kill Ogres outside of Elven City until you have Collected 10 Ogre Horns from them.
3. Kill Banshees outside of Elven City until you have Collected 10 Ice Crystals from them.
4. Kill Satyrs outside of Elven City until you have Collected 10 Nightmare Wands from them.
5. Kill EyeBalls outside of Elven City until you have Collected 10 Black Humus from them.
When the relationship points between you and Arthurian have reached 200 and 500, Arthurian will ask you to give him one 15-star Atk-def eudemon each time.
When the relationship points between you and Arthurian have reached 1000, Arthurian will offer you the power of being able to summon 3 Eudemons at once.