Q: Regarding Odin and Behemoth FATE Congestion, Display Issues, and Server Crashes
A: In order to avoid CPU stress when a large amount of people gather together, fields are rendered using 8 meter grids. Furthermore, these grids are not focused around your character, but rather the areas of the zone.
In a single grid, a maximum of 100 characters will be displayed. Since NPCs and monsters have display priority, the monsters themselves do not actually disappear, but once more than 100 players enter a grid, certain characters are no longer displayed. The system was set up to hide objects from other grids, so even if hundreds of characters gather, stress is not placed on your PC.
However, there is one problem. If, for example, Behemoth is in a certain grid, and the amount of characters in that grid exceeds 100, no matter what happens he will always be displayed within that grid. However, there is no display priority for adjacent grids. In short, if you're not positioned in the same grid as Behemoth, you won't be able to see him when the area is crowded with hundreds of players. If you move to the grid where Behemoth is located he will always be displayed, but once he moves to a different grid he will disappear again.