Hypnotic vision is Kumboh's gift to temporarily confuse individuals.
This power worked by Kumboh looking directly into the intended target's eyes; anyone who looks becomes temporarily stunned, confused, and disoriented. While using this power, his eyes turned a pearl white. Once he looked away, the target found themselves at a loss of memory.
The full extent of this power was never shown.
A subject had to look directly into Kumboh's eyes for this power to be effective. Since this power worked by sending suggestions into its targets' minds, it was most likely ineffective against Bella Swan due to her ability to repel psychic powers.
In The Groundskeeper, Kumboh stunned a night patron, leaving her confused, before walking in to visit Alice Cullen. When he walked away, she found herself unable to remember what she was supposed to do.