Patches quest starts in the Cathedral of the Deep. To trigger him spawning, .. go up to the entrance of the cathedral, from inside of the building, and open the double doors that lead outside. Then, head to the balcony to the left of the doors, and speak with him. If you have lit Rosaria’s bonfire before speaking to him here, then he leaves the cathedral, and his quest skips to the next step. Patches questline co-insides with 2 other NPC’s, Greirat, and Siegward. If you are completing their quest through Patches, .. then Siegward’s quest commences at a later stage.. after Patches saves Greirat from Irithyll. Speak with Patches here, then get trapped. And meet him on the other side of the bridge. Cross the bridge, and if you’ve killed all the Giants, you get a unique piece of dialogue. Now, go and confront the snakey bastard in all his treacherous glory.
You will find him on the way to Rosaria’s Bed Chamber. At this point, you can either buy Siegward’s armor and continue on with Siegward’s quest, or, you can leave the onion armor in his inventory to progress Greirat’s quest through him. Go and exhaust Patches dialogue here, then the next step to his quest is in Firelink Shrine. Buy the Tower Key off the Handmaid, and head to the top of the Firekeeper Tower. (If you went to Rosaria’s Bed Chamber, and skipped Patches first encounter i n t h e c a t h e d r a l, then he will move straight onto this step, and possibly glitch your game.. allowing him not to sell the Catarina set, or, care about Greirat’s plunders, for this whole playthrough). Head to the top of the tower… and the gate will lock behind you. Patches has fucked with your day for the second time.
If you opt not to forgive him for this, you will get a Rusted Gold Coin as a bribe, and the “Prostration” gesture, if you already do not have it. After you’ve sprung from his snare, by warping or escaping, go back to him in Firelink and find out what his true intentions were. (Ahhhh ye, wateva ya say boss). At this point, if you have not bought Siegward’s armor yet, progress Greirat’s quest up to the Irithyll plunder .. and tell him to plunder Irithyll. Then speak with Patches. Next, defeat Pontiff Sulyvahn when Patches is absent from Firelink Shrine, and Greirat will be safe and sound in Firelink. Now.. it is safe to purchase the Catarina set, off of Patches. After discovering Lothric Castle, Send Greirat to plunder the area. Then inform Patches where Greirat went. Patches will leave Firelink Shrine until you kill a boss.. And, once he is back, he will sell a “Hidden Blessing”. (Take two!..) This concludes Patches questline. I think due to time constraints they forgot to cut that dialogue there.. But in my opinion, the first take he did, was better ^~^.
Hmph. Thank you for watching. May the Flames guide thee. .
As found on Youtube