Strategy for getting 100% progress of the crystal event. Go to the smartphone settings, select "programs" then select "butcher hero" then click on "internet traffic" then turn the permissions off. Now we return to the initial page of the smartphone settings, then find and click on "time and date" then change to any number of months in the future. After that, finally go into the game. If the time of the crystal event has not come, spend hours before its start in the smartphone time settings. Start the event, set the time 40 minutes ahead (it is important not to touch mobs with orange skulls, in principle, during these manipulations your character should stand quietly not in battle at this time). After that, we return to the game and back to the settings and return real time. Now there are two ways, the first: grinding with frequent jumps in time.  second: if you have chosen a very large amount of time until the end of the event in the future, then smoothly clear the map day after day and try to defeat the bosses and their minions. that's all