The grimoire card that you're taking that from says word for word "No one can open the Vault alone. I opened the Vault. There was no one with me but I was not alone." Everyone already figured this part out, it has nothing to do with your theory. The story goes Kabr had a team, he doesn't know who they are/were neither do we. We also figured out that the Oracles and Gorgons don't exactly kill people. They actually wipe you clean from time itself, they erase you, make it so that you never existed in the first place. That's what happened to Kabr's team, they were erased from time, any memory of along with it. Kabr must have had very strong ties with his team mates because although he was alone, he felt a presence, as if there were other with him. He has no idea who they were, but just that haunting feeling as if he had help to begin with lingered with him till the end, yet he never figured it out most likely. It's actually very sad. If your friends die, you're devastated, but you have their memories and their legacy to carry on. You can move on without ever forgetting them, always a part of your heart. Kabr on the other hand doesn't even get to enjoy the memories of his team mates. The Vex wiped them clean from existence, including any memory or data on them so no one will ever know who they were. Their legacy, their memories, their lives, all gone. That is why the stranger called the Vex "so evil that they despise everyone and everyone despises them, including evil itself." Pure monsters.