In order to make more money they made the regional events and special events impossible to complete unless you spend more, and sometimes at all completable, every week a new toon wich does not give the chance to upgrade properly couse you'll need to spend again to buy rare materials and if you manage youl be using the toon once or twice in a year, example on regional event- cosmic 2 march - my team of 3 year's 385k against last stage more than 400k heroes with immunity, and nobody's reading it