Logic Masters Deutschland e.V.

The "Rank" rules in this puzzle are borrowed from the fantastic Rank Up series by my favourite setter, ThePedallingPianist.

The two-character "Rat Run" rules come from Mousetrap? (A Rat Run Homage) by tallcat.

For another excellent puzzle with a similar concept, I highly recommend this one.

Sorry for the long rules. Wish you a great day and happy solving!

Rules:

• Sudoku: Within the inner 5x5 grid, fill every cell with a digit from 1-5 such that digits do not repeat in a row or column.
• Full Rank: A value in an external cell represents the rank of the number formed by reading the digits in that row or column from that direction, where (1) is the lowest such row or column and (20) is the highest.
  N.B. If two ranks are tied, the value in both external cells is the lower of the two ranks being shared. For example, if the lowest four ranks are "12453", "13524", "13524" and "15432", the values in the relevant external cells would be (1), (2), (2) and (4) respectively.
• Corner Cells: The four corner cells of the 7x7 grid are initially unconstrained. They may contain any number (even including non-integers) at this stage. A specific rule for filling these cells will be revealed after the inner 5x5 grid is solved.
• Rat Run: The rat must reach the cupcake and the cat must reach the escape hole by finding paths through the 7x7 grid.
  - Individually, their paths must not visit any cell more than once, cross itself, or pass through any thick red walls.
  - As well as moving orthogonally, both the rat and the cat can move diagonally if there's a 2x2 space in which to do so, but may never pass diagonally through a round wall-spot on the corner of a cell.
  - Importantly, the paths of rat and cat can cross each other. This can only happen when their paths are perpendicular to each other and if it does happen, both paths must continue on to another cell in a straight line.
  - Just for clarification and simplification, the rat's path cannot pass through the cat's starting cell (R4C5 of the inner 5x5 grid).
• One-way Doors: The rat and the cat may only pass through pink arrows if moving in the direction the arrow is pointing. An arrow always points to the smaller of the two values it sits between.
• Slow Thermometers: Individually, both the rat's path and the cat's path act as slow thermometers. Along each path, from its start to its end, the values must not decrease.

Play on SudokuPad

(If the emojis don't display correctly in your browser, please refer to the image above. I'd also really appreciate any advice on how to fix this technical issue!)