You attempt to puppet the body of a creature that you can see within range by magically controlling its blood.

The target must succeed on a Constitution saving throw or else become afflicted by the spell for the duration and restrained until the start of its next turn. It repeats the saving throw at the end of each of its turns. On a success, it is no longer afflicted by the spell. Once a creature has succeeded on the Constitution saving throw, it can't be afflicted again by this casting of the spell

At the start of each of a creature's turns while it is afflicted by the spell it must make a Strength saving throw. On a failure, it is paralyzed until the start of its next turn. Alternatively, instead of making it paralyzed, you can choose to control its movement on its next turn and make it use its action on that turn to attack a target of your choice, with disadvantage on its attack rolls and moving at half of its speed On a success, it is restrained until the start of its next turn and nothing else.

Until the spell ends, you can use an action on your turn to try to afflict a new target that you can see within range. The last target stops being afflicted by the spell, and the new target must make the initial saving throw.