Puzzle #135 - Classic Sudoku

This puzzle, entitled "Boomerang", showcases a nice setup for a situational advanced solving technique. By design, it's supposed to be very difficult without spotting my intention, and to yield fairly painlessly once you find its secret. 

The clearest lens through which the technique can be understood is "truths and links", a framework which generalises many of the most well-known Sudoku solving techniques and opens up a vast number of possibilities for ad-hoc applications such as this one.

Rules

Place a number from 1 to 9 into each empty cell so that every row, column, and bold-outlined region contains every number exactly once.

Difficulty: 10/10



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