OP's lawyer: Sounds legit to me.
@OP: Did you have a lawyer to review the weird clause before signing it? Was it your lawyer?
1. Ask for references of prior companies they have funded.
2. Identity mutual contacts with someone you both know and can verify their credibility.
3. Ask around their reputation of other VCs and people in the space.
https://en.m.wikipedia.org/wiki/Consideration_under_American...
https://en.m.wikipedia.org/wiki/Consideration_under_American...
An illusory promise does not count as consideration, and the courts would probably force the investor to pay up the money or, if there were no promises made, the co tract could be overturned on grounds of lack of consideration.
https://legal-dictionary.thefreedictionary.com/consideration
I would not treat him as an investor and instead talk to a lawyer about putting him on notice that you’re prepared to sue him for tortious interference with your business. The other comments here about the requirement of consideration are correct. Also relevant: unjust enrichment and restitution [0]
I’m 100% speculating because you haven’t supplied enough information. The most important part of your post should be the actual language.