Nice work it's a good prototype/starting point! Just want to make a few points, from one UE4 dev to another, that will hopefully help.
The atmosphere and aesthetics for the game are really excellent, I can definitely see the Bloodborne influence there. Do you plan the replace the assets with your own? I don't think the models from the Elemental Demo were intended for gameplay (it was a sequencer demo if I remember correctly) and probably not as well optimised as gameplay assets should be. The volumetric fog also tends to tanks performance when you use it on a directional light across the whole map. I seem to remember a GDC video covering some great ways to localise it to the specific playable areas: "Volumetric Fog and Lighting in Unreal Engine 4 | GDC 2018"
Sound design is also well done for the most part but I noticed a very harsh transition from the outside to inside area, probably just a prototype thing but thought I would point it out. A lack of music (even a temp track) for the larger boss fight left it feeling very anti-climatic too.
I would also be very wary of using licensed music from Bloodborne in your trailer on YouTube. I know it's just for your prototype, but you are still breaching copyright on another artist's work and you may have your video taken down. I'm working on a VR gothic horror project and have been writing my own music in a similar style. I have a few tracks that I probably won't use so if you want one, let me know and you can freely use that without worry. :)
Keep up the great work and I look forward to following this project as it develops.