5 friends started an app together: The idea guy, a designer, backend, android and iOS engineer. The friends worked on the app for roughly a year however the idea guy started getting more and more angry about the project taking too long to finish. Eventually he started threatening us to shut down the project if we don't work faster and tried to replace members.
We refused and he eventually 'stopped' the project by removing access to all servers and cancelled paid accounts to Github and Co (most of them were held by shared accounts where he wasn't even the one paying them)
Now, the 4 of us are not happy about this at all since we worked for 1 year almost every day on this thing and in our opinion this 1 guy does have no right to decide whether the project is dead or not so we want to finish it without him: Put together some money, re-purchase servers and so on.
The idea guy incorporated a real company on paper but none of us signed anything, nor did he pay any of us. There are also no patents or anything like that. (When we asked him a few times to finally get the paperwork done he always avoided the question which seemed to be like he never really intended of sharing anything with us from the beginning.) The idea guy also mentioned very strongly that this idea is his property and he will pursue legal actions if we do anything without him.
Certain assets like sounds, a few graphics and the project name were created by him which is obviously his IP. If we were to remove this, could the 4 of us legally continue with the project under a different name?