Elden Ring Shadow of the Erdtree St. Trina & Thiollier Questline Walkthrough

The NPCs called St. Trina and Thiollier have a secret side questline in Elden Ring Shadow of the Erdtree DLC. This walkthrough shows the full solution. Completing this questline makes it possible to summon Thiollier as an ally for the endboss, making the final fight considerably easier.

Missable Warning: Steps 1-8 must be completed before burning the Sealing Tree at Church of the Bud. Steps 9-12 must be completed after burning the Sealing Tree. The Sealing Tree is the point of no return, most NPCs and their questlines become unavailable after this point.

Video Walkthrough

Step 1: Find St. Trina at the end of Stone Coffin Fissure. To entrance to The Fissure is at the southern tip of Cerulean Coast (very south of the map). There is a big crater, you must drop down from one ledge to the next until you reach the bottom. Then you go through The Fissure dungeon. At the end you reach the Fissure Depths site of grace, after it you must jump down the end of the path into the abyss, which leads to a secret area with the Putrescent Knight boss. After this boss you find St. Trina at the Garden of Deep Purple site of grace. The path can be a bit tricky, refer to the video walkthrough for the exact paths.

Step 2: Talk to Thiollier at “Pillar Path Cross”, tell him of St. Trina’s whereabouts. MISSABLE WARNING: Doing this will fail Moore’s Questline (do Moore’s Questline first if you want the rewards from it).

Step 3: Fast travel back to St. Trina, Thiollier will be there now, talk to him.

Step 4: Talk to St. Trina, imbide her Nectar 4 times, you will die each time and respawn. Keep doing this until she talks to you during the death screen (after 4th death).

Step 5: Talk to Thiollier in front of St. Trina, exhaust all dialogue and pass on St. Trina’s words to him. He will get mad and say “I will never forgive you”, because his jealous that St. Trina talked to you and not him and thinks you are lying. This is the normal outcome here.

Step 6: Imbide St. Trina’s Nectar once more to die.

Step 7: Go back to St. Trina, you will get invaded by Thiollier, kill him (he drops St. Trina’s Smile). He will disappear from the game temporarily but he will respawn after burning the Sealing Tree in Step 9.

Step 8: Keep drinking St. Trina’s nectar until she keeps repeating the same lines. I drank her Nectar 7 times total including all previous steps, do it until she repeats “You must kill Miquella… You must grant him forgiveness.”

Step 9: Burn the Sealing Tree at Church of the Bud to advance the story. You must have defeated Messmer at the top of Shadow Keep Storehouse to be able to burn the tree. POINT OF NO RETURN: Burning the Sealing Tree will make most other NPCs disappear and their questlines are no longer doable. Finish up any side quests before doing this. Make a save game backup here if possible.

Step 10: After using Sealing Tree return to St. Trina’s cave to find Thiollier on the ground. Exhaust all dialogue with him and tell him St. Trina’s words again, then drink her nectar again. Talk to Thiollier again and the last dialogue he should say is “…AH-HA…”. This means you finished the steps correctly. You have to complete this BEFORE fighting Leda and her Allies in Enir-Ilim. Thiollier disappears after this and the quest can no longer be finished.

Step 11: Proceed through Enir-Ilim area until you must fight Needle Knight Leda and her allies. Summon Thiollier before the fight by interacting with the golden summoning sign (before interacting with Leda’s red summoning sign). If you did Sir Ansbach’s questline you should summon him too as it’s needed to advance his questline.

Step 12: When you reach the endboss you will be able to call Thiollier for help by interacting with his golden summoning sign before the gate to the boss fight. He will assist you which can make the final boss easier. Thiollier will drop his full set after the endboss fight: Thiollier’s Hidden Needle, Thiollier’s Mask, Thiollier’s Garb, Thiollier’s Gloves, Thiollier’s Trousers.

If you finished Sir Ansbach’s questline you can summon him for the endboss too, he will also drop his full set afterward.

This finishes the side questline of Thiollier and St. Trina.

For all other NPC questlines refer to Elden Ring Shadow of the Erdtree – All Side Quests.