Logic Masters Deutschland e.V.

Over the holiday season this last year I had the honor of creating a secret satan puzzle for The Book Wyrm and had an absolute blast making this thing. It's definitely hard and requires much contemplation over implications before headway can be made, but the deductions are quite satisfying once they are found. Not a puzzle for everyone, but a beautiful monstrosity to those who will find enjoyment in it. :)

Rules

Fillomino:
Divide the grid into regions of orthogonally connected regions, and place the region size into each cell of those regions. The thick cell wall in row 9 indicates that the cells it separates are in different regions.

Full Rank:
The rows and columns of the 10x10 grid can be read in each direction to form 40 numbers of varying lengths. Order these numbers from smallest (rank 1) to largest (rank 40). For 2-digit numbers read the tens digit first when reading left to right or top to bottom, and the units digit first when reading right to left or bottom to top. There are no tied ranks in this puzzle. The inequality symbol between two columns points to the smaller of the two full rank clues.

If a full rank number starts with a zero, that leading zero is ignored.
(i.e. a row ending with a 10 would read as xxx10 from the left and 1xxx from the right.)

Penpa link
SudokuPad link (answer check only on single digit cells)