The first time you encounter Thops, you will do so at the Church of Irith in Liurnia of the Lakes. This church is located at the most southern tip of the lake. Talking to him here (including donating 10 ruins to unlock him as a sorceries vendor) will reveal that he wants to return to the Academy of Raya Lucaria, but in order to do so, he requires an Academy Glintstone Key. However, in order to obtain one, you must donate 10 ruins to him first.
Where to Find the Academy Glintstone Key for Thops
After you have obtained your very own Glintstone Key to the Academy from behind the Glintstone Dragon Smarag, make your way through the Academy until you reach the battle with the Red Wolf of Radagon in the Debate Parlor of the Academy. After you have vanquished him, proceed through the door located to the north and keep going until you reach a sizable inner court. Continue to the left until you come to a large pile of rubble that is covering a staircase.
You will find two Glintstone Sorcerers if you climb the rubble to the north and then continue up the stairs. Make a sharp turn to the left rather than proceeding forward through the covered walkway. Make your way down the stairs below.
Carry on up the stairs, and when you reach the top, turn left (towards the south), and you will see a body slouched over the railing. the side of the courtyard that faces left. Proceed upwards towards the northwest, where there is a pile of rubble rather than stairs. Proceed upwards, then turn left and ascend the stairs that are directly ahead of you. A dead body will be found dangling over the ledge in this area.
After you have climbed onto the rooftops, continue to the south along them, avoiding the Marionette Soldiers, until you come to a building to your right that has a ladder leading up to its roof.
Climb up this ladder to reach a rooftop that is very long and very narrow. Proceed with extreme caution because there is an additional Glintstone Sorcerer and three Avionette Soldiers hiding in ambush ahead of you. After you have vanquished these foes, proceed along the rooftop and then make a sharp turn to the right. Keep an eye on the ground below to find another rooftop to climb.
Keep going north and jumping to the rooftops below until you reach a point where there are no more options going north. You will see another set of descending rooftops if you turn to the left (west), and if you look to your right, you will see another Marionette Soldier standing watch on the roof below you.
After you have killed him, look below you and to your left (northwest) to find a ledge that leads to the next area. Proceed with caution as you descend and continue to follow it around the building until it reveals even more rooftops below you that are being patrolled by several more Marionette Soldiers.
Jump down to the rooftop in the shape of an oval below you, eliminate the foes that you find there, then work your way around the rooftop in either direction to get to the open windows that lead into the rafters of the Debate Parlor.
You can access the room through whichever window you deem most appropriate. Once inside, look down to find a chandelier that is supporting a body and an item. You are going to require the Academy Glintstone Key in order to complete Thops. Grab it after making your way down the platforming carefully, and then make your way back to Thops in the Church of Irith.
You will receive the Erudition gesture as a reward for going back to Thops and giving him the Academy Glintstone Key. This will also allow you to progress through the next and final part of his questline.
Where to Find Thops at Raya Lucaria
You need to go back to Raya Lucaria and find your way to the classroom in the schoolhouse (the easiest way to do this is by warping to that Site of Grace). Leave this room through the door on the west wall, and after a short distance, hang a right around the building’s perimeter to find Thops.
The Thopps’ Bell Bearing and an Academy Glintstone Staff can be stolen from his corpse if you loot it. Thus concludes Thops’ questline.