I finally return post POTE with my latest Gren Maju build.
There have been numerous changes to the deck now both Spright and Tearlaments have entered the fray.
Put simply the deck still has 2 rather simple plans. Plan A is to overwhelm and OTK the opponent. This is achieved through the use of powerful board breaking cards and big beatsticks in easily summonable LV 8 monsters, Numeron Dragon or Gren Maju itself. Plan B is to clear the opponents board to and get access to either 4 material Zeus, allowing two board wipes during the opponents turn, or using other Rank 8's such as Sanaphond to shut off graveyard summoning or Hope Harbinger to negate spells.
The baord breaking is achieved in many different ways. Kaiju's (Gadarla is still the best choice as Floowandereeze still exists) tackle anything particularly oppressive/non-targetable. Alpha Beast syngergizes so well with Kaiju's due to it's effect that return cards to the Hand/ED (non-targeting I might add as well). As Alpha can special summon itself more than once using its effect, you can loop Gadarla back to the hand, to then Kaiju another particularly troublesome card and then summon Alpha again, depending on what the other cards in you hand are. These two cards alone can eat through several layers of monster interruption quite easily. The Danger cards are really solid. Not only are they big bodies, their board breaking effects on discard also can force negates too. Danger Jackalope is an immense extender for the deck, either facilitating link climbing via summoning itself, or allowing easier access to the rank 8 engine on discard. Ultimate Slayer is one of the best cards that this deck could have hoped for. Being able to return the likes of Mirrorjade to the ED so it's unable to trigger its grave effect (it triggers with Kaiju's believe it or not) is such a great tool, especially combined with N'tss for further board breaks of Garura to draw depending on the situation. Also handy to get rid of links like Halqifibrax if the opponent is relying on Scythe lock can also come up sometimes or Apolussa/Link 5 Borrel if you fail to draw into a Kaiju. The lack of a decent XYZ to send isn't ideal sometimes but still acceptable most of the time. Putting Toadally in simply wastes a ED slot, despite the flexibility the ED has.
The rest of the deck is dedicated to draw power, pushing through the likes of Ash and other monster effects and D-shifter/mass banishing cards to facillitate OTK's more easily. Gizmek/Pot Of Desires/ Eater mass banish to turbo charge Gren Maju, D-Shifter eliminates Tearlaments quite easily as well as most other decks. Even Spright hates the card, because you totally shut the Toad engine off, and if you break through the opening board they have considerably less resources to follow up with. Triple Tactics and Called By help push through the likes of Ash, Droll and other monster effects and Allure is useful for a draw 2 and to rid the hand of D-Shifter if it ends up not being the most optimal option (it overrides the use of Slayer, so choose wisely.)
The side deck is roughly the same as it always has been but with some changes. Ra Sphere remains godly against Adventurer/Synchro/Therion reliant decks, as well as being a massive blow against Spright. Heat Wave basically stops your opponent summoning on their turn, which when playing all the decks it works against, almost certainly facillitates an OTK on your next go. 2 Twin Twisters and Reboot are all that is needed against backrow, as there are already so many inbuilt ways to get destroy spells/traps in the deck already. D-Barrier shuts off most lines for the current top decks rapidly reducing the chance of being OTK's to then swing and OTK in return and Deck Devastation Virus is the new way to combat both Splight and Floowandereeze because it's condition to tribute a Dark monster over 2000 atk is laughable trivial for the deck to do.