SudoKanard

 Full Rank Sudoku Apply classic Sudoku rules. Full rows/columns (read left-right, right-left, top-bottom, bottom-top) form 36 distinct 9-digit numbers. Their ranks from the lowest are given. Solve on Penpa: https://tinyurl.com/2laz99vw

 Battenburg Little Killer Sudoku Apply classic Sudoku rules. Whenever two odd and two even digits form a 2×2 chessboard pattern, a Battenburg marking is given. If there is no marking, the above pattern is not allowed. Each clue outside the grid indicates the sum of the digits contained in the cells in the direction of the corresponding arrow. Solve on Penpa: https://tinyurl.com/2ld3ktjp

 Position Sums Sudoku Standard 6x6 Sudoku rules. On each row, the leftmost two digits are A and B. An unshaded number in the left margin is the sum A+B of the corresponding row. A shaded number in the left margin is the sum of the Ath and Bth digits in the corresponding row starting from the left. The same applies to columns starting from the top. Solve on Penpa: https://git.io/JgAG2

Arrow/Thermo/Quadruples Sudoku "400 subs"     Standard Sudoku rules apply. Digits strictly increase along each thermometer starting from the bulb end. The digit in a circle is the sum of all digits along the arrow attached to the circle. When a circle overlaps four cells, the digits in the circle must appear at least once in the four cells.   This puzzle celebrates 400 subscribers to the YouTube channel SudoKanard.   Solve this puzzle on SudokuPad:  https://tinyurl.com/2be2y54h

 Easy as Japanese Sums Place a number from the specified list into some cells so that every number appears exactly once in each row or column. Cells may remain empty. Each number outside the grid indicates the sum of the first continuous group of at least one number (including “sums” of a single number) that is encountered in the respective row or column from the respective direction. The group ends at the edge of the grid or a cell without a number. Some cells might be marked with a cross; do not put any numbers into those cells. Unlike a standard “Japanese Sums” puzzle, it is not possible for numbers in the list to be missing from any rows or columns. Solve this puzzle on Penpa: https://tinyurl.com/2nldx92u

 Quadruple Sudoku Standard Sudoku rules apply. Digits in a circle must appear at least once in the surrounding four cells. Solve on Penpa: https://tinyurl.com/yxuobgtg Solve on SudokuPad: https://tinyurl.com/36v2ypwu

 Killer/X-Sums Sudoku Apply classic Sudoku rules. The digits placed in each marked cage must sum to the total given in its top-left corner. Digits must not repeat in cages. Each clue outside the grid indicates the sum of the first digits placed in the corresponding direction, where X is equal to the first digit placed in that direction. Solve this puzzle on Penpa: https://tinyurl.com/2rybmlhj