Shareholder is blocking every decision even though he owns a minority stake

This is essentially a deadlock situation created by the unanimity requirement in your own articles of association, and the remedy will largely depend on exactly how those articles are worded regarding decision-making thresholds. Under the Companies Act, Chapter 386 of the Laws of Malta, you may be able to pursue a formal amendment of the articles to change the voting threshold for the specific categories of decisions being blocked, though this itself may require a qualified majority or unanimous consent depending on how the articles were drafted, which can be a chicken-and-egg problem. If informal negotiation fails, Maltese company law also allows a shareholder to apply to the court for relief where the affairs of the company are being conducted in a manner that is oppressive or unfairly prejudicial to a shareholder's interests, and a persistent, unreasonable block on essential operational decisions could potentially support such an application. Given the personal and financial stakes involved, this is a situation where consulting a corporate lawyer to review your specific articles of association before taking action is strongly advisable.