@sabby_e17
I'll try to give you a good tip about it's location:
Remember the left part of the stage, in which at the top you had a Blue Eyed knight guarding a fog gate? If you pass that fog gate, you'll reach a descending stairway which housed a corridor in which at the end there was a doorway with oil barrels and a soldier who threw a firebomb to explode those barrels.
After descending the stairs that I told you, if you look down in the beginning of the corridor, you can see a small ledge in which Ostrava is waiting for you to help him, or was if you had already helped him. If you press your character against the ledge of the corridor, he will hop over and jump to the platform where Ostrava is/was.
In that ledge you'll find the Thief's ring
Current PC Build
CPU - i7 8700K 3.7 GHz (4.7 GHz turbo) 6 cores OC'd to 5.2 GHz with Watercooling (Hydro Series H110i) | MB - Gigabyte Z370 HD3P ATX | Gigabyte GTX 1080ti Gaming OC BLACK 11G (1657 MHz Boost Core / 11010 MHz Memory) | RAM - Corsair DIMM 32GB DDR4, 2400 MHz | PSU - Corsair CX650M (80+ Bronze) 650W | Audio - Asus Essence STX II 7.1 | Monitor - Samsung U28E590D 4K UHD, Freesync, 1 ms, 60 Hz, 28"
