The man who conned me for 6 months argues cases for a living

I will try to keep this short.

I dated a guy for nearly 6 months but we were never exclusive as he "wasn't ready to date due to mental health reasons". We got super deep on an emotional and intellectual level and I gave him his idea for his startup and got it off the ground for him (connected him to everyone I know etc). I eventually got sick of the grey area and gave him an ultimatum and he told me he thinks he might be bisexual (which he claims he has never told anyone) but really wants to be with me and begged me not to leave. A few days later, I asked to meet and told him I don't see how this will work. He teared up and begged me to take the weekend to think about it - I said okay. He tells me he is going to his parents for the weekend to reflect on "us" and to tell his parents about his bisexuality. He sends me detailed messages about how nervous he is to tell his parents, calls me - the whole thing - a very calculated and detailed lie. Long story short - I find out he is in Paris with another girl instead. I confront him, he cries and admits he is a compulsive liar etc. He also told me he ended it with the other girl to be with me (and begged me not to reach out to her), so I obvs immediately hey-girled her and he had lied about ending it too. We compared notes, the day he told me he thinks he is bisexual he called her after telling her he misses her while texting me saying how amazing I am and how thankful he is for my reaction. I gave him months of my time (literally 100s of texts a day, multiple calls a day), my network, the startup idea and even my dad (a dr) who helped him with his chronic pain. The detail that makes it: he does this for a living. He's a litigation lawyer.

Revenge ideas, mildest to most severe (and the bottom ones are more 3am fantasy than plan):

• Do nothing (already blocked him everywhere, reported him on Hinge)
• Show up at his flat with the other girl to return his things
• Message his older brother laying out the behaviour, for accountability
• Email his employer the startup contract he wrote (a direct breach of his employment duties)
• Email the bar and try to get him disbarred (not even sure that's possible)

Thanks in advance fellow redditers