Short character voice clips like this Ashe woohoo spread through soundboards, Discord servers and short video edits because they say a whole mood in about a second. Players started saving the cheer as a standalone reaction separate from any full match or cutscene, using it whenever something went right. Its popularity comes from how instantly readable it is, even out of context, so creators who have never used the character can still drop it for excitement, relief or a comedic over the top celebration.