[Endoperez]

The spell itself is a ritual, which creates vinemen. Vinemen are mindless units. Mindless units die, instead of retreating, if all commanders are dead or routing. Normal commanders who don't know magic can command Vine men, while mindless undead need a Death or Blood mage or an undead commander. They would die if living commanders are left, but all commanders that could command undead are dead or routing.