"Once every two to four months. The same Endbringer never attacks twice in a row since the Leviathan showed up. I'm not sure if you know, but our version of Japan has been mostly destroyed by the Leviathan, with Kyushu having been completely sunk. You probably saved Newfoundland from a similar fate, but the Behemoth has caused similarly extensive damage and it's basically impossible to gauge how much the Simurgh has affected."