This is again a harder puzzle. I don't know exactly how hard it is, but there's definitely no progress to be made if you don't understand the opening. I wasn't expecting to be able to make this variant without any givens. But I managed to create an opening that works without any givens. I think it's a nice and interesting opening. The middle is probably a bit easier, but I think the end is again a little bit harder, but worked out nicely in my opinion. I'll think about making something easier again next week, but I can't exactly promise that. When I find an interesting opening, I just run with it. And interesting is generally hard. Enjoy this puzzle though.
In this Sudoku, the symbols indicate the relation between the sums of the 2 cells on either side of the symbol.