Annoyed by the slow but steady decrease in strength of the muscles in his back, Iṃgor uses the levitation spell to compensate for the lost strength, as it can apply a force in any direction the user desires.
Occasionally he turns around, shooting an arrow at one of the wasps' wings. Their chitin exosceleton is too hard to be penetrated by normal arrows, but the fragile wings are a suitable target to effectively ground them.
Afterwards he starts running again, as it can be hard to take aim once the wasps circle around one.
He repeats the process multiple times, until he arrives at Nickolaus' location.