what/where/who the blazes...?

the blazes

Used as an intensifier after a question word (who, what, where, when, why, and how) to express extreme confusion, surprise, or aggravation. Primarily heard in US. And just how the blazes am I supposed to have three reports done by 9 AM tomorrow? Where the blazes did you find that rusty old car? Who the blazes is making all that noise?
See also: blaze
Farlex Dictionary of Idioms.

what/where/who the ˈblazes...?

(old-fashioned, spoken) used to emphasize that you are annoyed and surprised, to avoid using the word ‘hell’: What the blazes have you done?This expression refers to the flames associated with hell.
See also: what, who
Farlex Partner Idioms Dictionary
See also:
  • in (the) blazes?
  • the blazes
  • in blue blazes?
  • in thunderation?
  • tarnation
  • in tarnation?
  • what in tarnation
  • in creation
  • in creation?
  • (in) the devil