I've said before I liked Magnets puzzles. So I've tried to experiment with them a bit. The Tapa inclusion worked really nicely. For this one I went another way.
I came across the Tateyoko puzzle on Naoki Inaba's website. Here the goal is to divide the grid into Domino regions. An O on a border indicates that the lengths of the sides touching there are the same length. An X on a border indicates that the lengths of the sides touching there are of a different length. I then realised, basically you are building Magnets puzzle grids. So I figured it would be worth trying to combine them.
I first started with a 10x10 grid and found a bit of a start. But I realised this way it would turn out far too hard. So I scaled it down to an 8x8 puzzle. It's still not particularly easy, but it's more doable than the 10x10 opening. I'd advice getting some practise with the Tateyoko part of the puzzle by going to the link given above.
Rules for Magnets
Follow normal Magnets rules. Additionally in this puzzle, the domino regions in which the magnets go aren't given yet. Instead you have to construct them. Some borders between domino regions are already given. If there is an O on a border, it indicates the lengths of the sides touching there are of equal length. If there's an X on a border, it indicates the lengths of the sides touching there are of unequal length.