The use of elixirs is bugged too. It says that you can use 1.000 elixirs, and I supposed that this phrase was a mistake. But later I made some horrible mistakes and Nicholas killed me when she was at like 1% of life. Half as a joke, I tried to use an Elixir...and it worked. If I had known that, I haven't used it.
Even more joke; After having a TPK and use an Elixir, the game marked as cleared the missions of Soul surviving and 5 survivors. After all, everyone was alive on the end, right? XD