The following list explains how to get the Masters.

Abbess: Talk to her in the Village of Chek after talking to all the dragons in their physical forms.

Bunyan: Get the ability to apprentice with all the other eleven Masters. Then, find Bunyan by going to the question mark spot above the Highway and go through a secret passageway mid-way through the mountain range. Go up to his hut and talk to him.

Gyorim: After getting over 3,000 points in fishing, talk to the fishing frog in Lyp.

Kahn: After defeating him for the third time you can find him on the upper west continent in a question mark spot near the flowing tides.

Kryrik: After the sea voyage event, return to Shikk and talk to him. He will apprentice you only if you have gotten 25 or more hits in a combo. Practicing in Chek is recommended.

Lyta: After the Sea Voyage, talk to Sister Lyta in the orphanage in Synesta. You must have already learned Ward for her to apprentice you.

Marlok: Buy the "treasure" from the frog in Sarai for 500 Zenny. Trade it around from city to city until you get a Tin Ball or better. Then, talk to Marlok in Synesta after finishing the sandflier event.

Momo: Just talk to her in the windmill in Wyndia

Njomo: After working with the Faerie Village after awhile, go to the question mark spot with the house in it. Talk to the fairy upstairs.

Rwolf: Just talk to him near the entrance of Kurok.

Stoll: Pay him all your Zenny in the Bandits Hideout after the Marlok events.

Una: After beating up Kahn for the second time, talk to her in Worent.