SudoKanard

Odd/Even Sudoku 6×6, two variants   Two practice puzzles for the upcoming Sudoku Mahabharat round.   Odd/Even Arrow Sudoku 6 ×6 Penpa link: https://git.io/JlTwA Standard 6 ×6 Sudoku rules apply. Gray circle = odd digit. Gray square = even digit. The digit in a hollow circle is the sum of all digits along the corresponding arrow. All digits in the circles in the first two rows have the same parity. Odd/Even View Sudoku 6 ×6 Penpa link:  https://git.io/JlTiN Standard 6 ×6 Sudoku rules apply. Shaded squares should contain even digits (2,4,6) while shaded circles should contain odd digits (1,3,5). A cell which is not shaded can contain a digit of any parity.   Additionally, an even digit outside the grid must be the first  even digit seen from that direction and an odd digit outside the grid must be the first odd digit seen from that direction.

 All or Nothing Killer Sudoku Standard Sudoku rules apply. Killer Sudoku rules apply: in every cage with a dashed outline, all digits are different and the number that may be written in the top left corner is the sum of all digits in the cage. When the sum is written with two different digits, either both digits are in the cage or none of them are. This applies even to cages whose sum is not specified.   This variant was invented by Erwan Bernard. Penpa link to solve online: https://git.io/JlJwm This puzzle was solved by Simon Anthony on Cracking the Cryptic: https://www.youtube.com/watch?v=uVYG5Jica1I

 Mathrax Sudoku   Standard Sudoku rules apply. Some intersections are marked by a number and an operator in a circle. The number is the result of the operation, applied to both pairs of diagonally opposite cells. A question mark means that the result of the operation is not given and has to be determined as part of the puzzle. An E in a circle means that all four adjacent digits are even. An O in a circle means that all four adjacent digits are odd. Penpa link to solve online: https://git.io/JWN6x  

French Revolution: from 1789 to 2021     Standard Sudoku rules apply. Thermo : digits strictly increase along thermometers starting from the bulb. Arrow : the digit in the circle is the sum of all digits along the arrow. X-Sums : each number on the left side of the grid is the sum of the X first digits where X is the first digit seen in that direction. Sandwich : each number above the grid is the sum of the digits that are sandwiched between 1 and 9 in the corresponding column.   Penpa link to solve online: https://git.io/JCqbr