Had to use temporaries to figure out large parts, but finally arrived at a logical conclusion each time. Found it pretty hard because of that, but also pretty cute. Thanks!
Hints for where I at least had to mess around with tempraries the longest: Both top corners are filled in.
I tested it to ensure it could be done logically, and I was able to solve it without using any temps. But it's definitely harder than any of my other puzzles.
That was unbelievably hard. Had to approach three times until finally could do it without mistake. Logical though, I think - not sure where my mistakes were from... each approach I was focusing on sth else though.