Puzzle#100: Century Sudoku

This is 100th Sudoku of this blog. Hope you like this. Please solve and provide feedback.

RULES:  Please read all the rules carefully as there may be slight changes in some rules.

Grid:

The grid contain four 9x9 sudokus assembled in one big 18x18 Sudoku. Please note that all 4 sudokus are independent of each other. So it is perfectly all right to have same digits adjacent to each other at boundaries. Be careful while solving.

Sudoku Types:

Thermo : Normal Thermo rules apply with no twists.

Arrow : Normal Arrow rules apply with no twists.

Little Killer : Normal Little Killer rules apply, just the span of Sum extends to different 9x9 grids.

Killer : Normal Killer rules apply, but repition of digits are allowed. 

XV : Normal XV rules but there is no converse rule, that means if X or V appears, it will just sum to 10 or 5 and has no effect on any other part of the grid whatsoever.

Quadruple : Normal Quadruple rules, however boundary can be decieving

Odd Even : Normal Odd Even rules.  This is how Odd Even cells look.

Extra Region : Normal Extra region rules. There are 2 extra regions at lower part of puzzle. This is how Extra region cells look.

Delimited Kropki : Normal Delimited Kropki Rules. There are 2 major loops with lines clearly marked. These line should obey Kropki rules along the lines with connecting cells. Here all type of converse rules are applied across these line paths.
Click for Delimited Kropki Detailed Rules

Coded : Certain letters appear in the grid. They can be mapped uniquely to digits from 1 to 9. No two letter share same digit. It is part of solving to find out the values of these letters.

Consecutive Pairs: In Grid there are some white dots given between 2 cells either horizontally or vertically. They obey consecutive rules. There is no converse rule which is applicable.

Happy Solving !!

I would like to Thanks Prasanna for test solving it very patiently.