Answer 1: The definition of the word transfix is to cause someone to become motionless with horror, wonder, or astonishment.
If you experience something that has the power to transfix you, the words you could use to describe the experience is astonishing, mesmerizing, hypnotizing, captivating, or astounding.
Answer 2: The second definition of the word transfix is to pierce with a sharp implement or weapon.
If you experience something that has the power to transfix you (Second definition), the words you could use to describe the experience is impaling, puncturing, slicing, or piercing.
PS: I don't know which context of the word you were looking for, so I decided on both since there was no background context.