One year ago I started a social media page with a partner with the goal of turning it into a business. Initially we divided work between us almost equally (posting the pictures, etc. however it was not much time investment), as we were both working full time for another company, and we were making little progress as the concept was not bringing any value to the users and we were not growing. In May / June I quit my job to dedicate myself full-time to the page, my partner didn't.
After 3 months of working alone on the project, completely changing the concept and the strategy, my solo work brought enough followers to justify starting an actual business (I grew the page from 100 to 15K followers in 3 months).
At the sight of this success, my partner is demanding a high stake in the future company, disproportionate to the amount of work invested, which was basically 0 from the time I changed everything. From my point of view T0 was the time when I completely rethought the concept and the strategy. And my partner is not interested to quit the current job and work on this full-time. My partner is demanding either a high stake or a huge amount of money, otherwise I was threatened with legal action in court.
Is it normal/ethical to grant my partner a stake in the company to be formed just for contributing at first (without any success back then)?