Promissary notes do not convey property, just obligation to pay for them. As Mr. KIA says above, you have no legal interest in the property. Real estate transactions have to be in writing. His conveyance to the LLC was stupid. Not only was it likely fraudulent. It also likely been easily challenged if the creditor wanted to attach it (depending on what the lawsuit was about, they might not have even had to challenge the conveyance). Third, he now doesn't own the property either. The LLC does and it's controlled by someone who is not him.
Your worst case is that he gives you nothing and you have nothing: no equity, no part ownership, period.
Home ownership with a friend is always risky. You don't even have that. You have a situation where you threw money into a situation without any legal expectation of getting anything in return.

