Logic Masters Deutschland e.V.

Normal sudoku rules apply.
Cages show their sums, and digits cannot repeat within a cage.
On thermometers, digits increase from the bulb.

But! One of the digits from 1-9 is a ghost, and is not bound by those constraints. The ghost digit still follows normal sudoku rules (appearing once in each row/column/box), but does not count toward cage sums, can repeat within a cage, and can appear anywhere on a thermometer (other digits on the thermometer must still increase from bulb to tip; the ghost digit is simply ignored).

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CtC

This puzzle has been featured on Cracking the Cryptic! Click here to watch Mark Goodliffe's solve.