I really love Gren Maju! Out of all the big swingy monsters that do nothing, he is the biggest one that does the least : ) When Promethean Princess, Bestower of Flames came to master duel I thought that it was actually a fun way to make Gren more searchable and also a way to bring it back if it gets destroyed early. So, this is my take on more of a toolbox deck with Gren Maju Da Eiza rather than just a turbo banish. It's been more of a going second deck deck that aims to finish with Gren, but because Gren isn't directly searchable, the deck is meant to clear boards and create smaller threats, and then if you get to a Gren it's over, but if not you can still win through disruption and Promethean Princess, Bestower of Flames
Tour Guide From the Underworld has been working really good as a way to grab Gren, then link off, then go into Promethean Princess, Bestower of Flames to bring back Gren. And it can go tour guide to link off into I:P Masquerena then put Spright Carrot into Princess to end on a can't be destroyed Prometnean and a giant Gren. Masquerena and Knightmare Phoenix have been really awesome to play around with, making Promethean Princess, Bestower of Flames unable to be either destroyed or destroyed by battle, and you can always bring phoenix back with princess to co-link. And, if the game gets really long and weird, one Knightmare Phoenix does co-link to 2 Promethean Princess, Bestower of Flames
The banish engine is pretty simple with Eater of Millions and Pot of Desires and things, but there is also a lot of discard to get either Gren Maju Da Eiza or Fairy Tail - Snow or Blaster, Dragon Ruler of Infernos in the GY.
One twist on this deck from an older version of Gren is that you do want to use the extra deck, so you do kind of have to be careful with Pot of Extravagance and Pot of Prosperity Because you want to get into the extra deck, you do have to be a little careful with what to banish and when to risk it.
Ultimate Slayer is a great interaction but it does have problems, especially into Kash, but I do like it because it also gives me a fire monster in the GY a lot to use with Blaster, Dragon Ruler of Infernos or Primordial Princess. Floow and Lab make slayer feel like a dead card, but it's master duel, you can't account for everything : ) Lava Golem could be a better option for the slot for a more competitive build, and Triple Tactics Thrust would probably be great to grab draw spells or breakers.
Since Pot of Extravagance has gone down to one I've been playing around with a lot of things and Chicken Game seems pretty good. The deck has a lot of ways to get it off the board, and if someone wants to play a long game it's great, plus the damage stipulation sometimes won't hurt your attacks because you can swing one big Gren and then they go from highest life to 0
The spright cards are mostly here as link creatures but they sometimes have nice utility, kind of the same for Fortune Fairy En A lot of the time these cards are going to get banished or discarded, so I wanted some things that are good but not bad to not have, if that makes any sense : )
I think that's kinda it, it's just Gren Maju Da Eiza being a big stompy monster, but I've been finding there are a lot of small ways to pilot this list that are effective. I don't know, I'm just having fun to have a link monster that supported Gren and trying to make that all work, because it kind of shouldn't, but it kind of does sometimes.
Any advice or ideas are highly appreciated. This was just kind of a random idea I had for a deck and it could probably be better.