The phrase comes from Italian World of Warcraft play, where mana is the resource casters spend on spells and healing, and running out during a raid can wipe the whole group. Clips of players shouting instructions in voice chat have long been shared in Italian gaming communities, and this stretched scream was clipped and passed around as a standalone reaction. It survives on soundboards because it needs no context, even listeners who do not speak Italian understand the panic, and gamers keep reusing it for any resource emergency.