So the banlist happened.... and Barrier Statue was taken away from the deck. Many people think that the deck is done as it's main win con is no longer available. Also, Kashtira easily plays around the secondary win con of the deck, D-Shifter with ease. They are wrong. Statue while strong, was at times just one big target. And D-Shifter is no longer needed in the main deck as Kashtira will likely rise to be the top deck of the format. This allows the deck room to now synergize more effectively with an engine that doesn't require the extra deck, and uses it for interruption and advantage. That engine, is Dogmatika...
The loss of Statue and relegation of Shifter to the side is more than made up for by the increase in main deck interruptions you can field. Nadir is both used to add/recycle Ecclesia, and also dump extra deck monsters that can either disrupt the opponent or gain further advantage. Ultimate Slayer removes most problematic boss monsters whilst also being able to dump ED monsters like Nadir for further uses. Slayer also has the added benefits of not being able to be stopped by monster negates. Evenly is also an incredibly strong card against many decks as well.Triple Tactics Talent/Thrust are self explainatory. Scary Sea has been added because Kashtira will be hard pressed to put anything of note up without having Kashtira Birth in hand. The rest of the deck is fairly standard, but instead of the usual end board of Empen, Statue and Dreaming Town/Map, you aim to have Empen, Ecclessia, Punishment and either Dreaming Town/Scary Sea depending on the deck you are up against.
Nothing of note really needs to be said about the Extra Deck except it's tailored to make best use of Ultimate Slayer and Nadir Servant. N'Tss/Garura provide extra disruption and advantage against fusion based strategies. Wind Pegasus and Omega offer disruption or recovering assests from the grave, as well as removing troublesome Synchro monsters. Mereologic is very strong to not only remove a key XYZ's monster (Arise-Heart), as well as negating another monster effect on the field (usually Unicorn). Zeus package never used but still useful and Tri-Brigade Omen/Ferrijit to add more monsters and fix hands, as well as helping to remove links such as Apolussa.
For the side deck. D-Shifter is purely for decks not named Kashtira/mirrors. An extra copy of Scary Sea and Unxplored Winds for greater chance of stopping Kashtira going 1st and board breaking going second. Harpie's purely because it's generically good against backrow. Solemn and Harpie's Feather Storm for floodgating your opponent or stopping potentially crushing cards and Eclipse mainly for Kashtira but may swap with Lightning Storm for more generic scenarios.