@Robbini They had panels of the elf drawn as the bad guy, so unless the one drawing the art i bad at his job, the elf was clearly intending to release either that griffon, or whoever it serves behind that door (the default reason would be vengeance on his fellow countrymen, as griffon seems to hate elves). So I doubt it is forgotten nor removed from records, and more likely simply that the guy knows from his country's/tribe's/race's (depending on authors creativity) records, but opted to not tell the powerless human scrub about it and few promises about treasures instead.
Then he met a windfall in terms of a guy from a specific clan, except it turns out to be his bane as the guy is too str0nk and kills the god he wanted to release for his vengeance/plan to rule the world/whatever.