The caster can make the victim carry out a command of the caster.
The command transmitted by the caster manifests itself as a "fixed idea" in the mind of the controlled. During the duration of the spell, this idea keeps entering the mind of the victim, as long as the victim does not give in to it, and sometimes it can even disturb his concentration on other things.
The caster can make the controlled do things that are not immediately life-threatening to him or go against his innermost principles. For example, a mage cannot be made to burn valuable books, but a paid henchman can be made to betray his master, or a mercenary to change sides in battle.
The spell lasts for Power minutes. Once a minute, the victim casts on his willPower. If it achieves less than the Power of the spell, it is convinced of the fixed idea and performs it.