Yotsmungand (ヨツムガンド Yotsumugando, also translated as Jörmungandr or simply Jormung) is a Dark Magic spell that is primarily used by Dark Mages in Genealogy of the Holy War and Thracia 776. Yotsmungand is a standard Dark tome in both games, as is the case with Flux in later games in the series, although it should be noted that its Might is higher than that of Flux.
When the Yotsmungand spell is cast by enemy units in Thracia 776, their targets will not just sustain damage when afflicted by the spell, but will also be poisoned. Unfortunately enough, this effect is absent when the spell is cast by player units, and alongside the fact that the tome in question is rather heavy, this can prove to be quite disadvantageous to the player. Despite this, however, using the Yotsmungand tome is the only method in which Salem's Dark Magic Rank may be increased.