These are roiling globes of magical energy that travel across the battlefield, wreaking all kinds of unusual (and often deadly) effects. The following applies to magical vortexes:
They do not have a target.
They must be placed in the caster's front arc.
They may not be used in such a way that they affect any models engaged in close combat when initially cast.
Models cannot choose to voluntarily move into/through a magical vortex.
A magical vortex uses one of the round templates, which is placed in base contact with the caster and with its centre within the caster's front arc, and then moves as described in the spell.
Unlike most other spells and other gaming effects that use templates in Warhammer, magical vortexes remain on the battlefield (unless they move off it). At the end of every subsequent Magic phase, each magical vortex moves in the direction and distance stated in the spell. If a magical vortex ever ends its move over a unit, place it 1" beyond the unit in the direction it was moving. If this is also over a unit it should be placed 1" beyond that unit, repeating the process until it is no longer touching any models. When this happens, models between where the magical vortex ended its move and where the template is placed are not affected by the spell.
Models that are forced to move into or through a magical vortex for any reason suffers the full effects of the spell as soon as the unit makes contact with the Magical Vortex (in the case of a spell that affects all models hit, every model whose base would pass into/through the vortex is affected by the spell). Surviving models are then placed 1" beyond the template and their movement ends.
Magical vortexes are always remains in play spells (see spell resolution).