u/taigaeskimo

I've beat the game and I've been going around Azuria during nighttime and killing monsters in the overworld and occasionally going into Dens to try to find Barrel Felynes. I thought I got a cutscene once but when I checked each map, there was no red X or no icon to indicate the presence of a spawned Elder Dragon. I've been repeating this process for an hour now and I have not been able to spawn anything. Am I doing something wrong?

An hour prior I did spawn Canalta's Elder Dragons and forced myself to die to reset the spawn but is it expected to be this difficult to spawn Elder Dragons? Do I need to do a quest or something to unlock spawn chances?