R6C36 has a naked pair on 3 & 9. With all of the pencil marks filled in and the naked pair accounted for a finned X-Wing on 9 will be revealed. There are other approaches to solving this puzzle, this is the one I would use.
It is a finned X-Wing. I think I left off the word "finned" the first time I mentioned it. It is in R24C67, with the fin in R4C5. Finned X-Wings allow eliminations only in the same block as the fin, so 9 can be eliminated from R6C6. The remaining normal X-Wing eliminations are invalidated by the fin.
Eliminating 9 from R6C6 forces the cell to 3, and everything else follows from singles.
I saw another naked pair in row 1 on 1 & 5 when I first did the puzzle, but it is not required.
As a general rule we prefer using new topics for new puzzles. However, if there is some relationship between the puzzles that you want to bring up it might be nice to put the new one here so the relationship can be explained without having to jump between two different pages.