Joahan.
I... knew that I'm here because of him. I could feel it. At the very end, I deceived you. I wasn't supposed to stay behind, but it was the only way. He was there with me.
What did you understand?
A vessel that could trap a soul? I suppose it shouldn't be impossible, but many great minds tried to achieve that. Trapping the magical energy is simple, in theory, at least, but everything that composes a soul... That is far more esoteric.
I'm not sure for how long your method would last, even if you completed the vessel in time, but it's a clever idea. I have something that might help with crafting that.