I've tried to make Gate Guardian as viable as possible for Masteduel ladder, but try as I might, the deck is still casual. It may steal a game or two (especially if the opponent doesn't read cards) but usually it gets outclassed and beaten.
I'm not going to make an in-depth guide for this deck since it's really basic to play and it's fairly weak. Basically, try to summon Gate Guardians Combined by sending to GY or placing on field Suijin, Kazejin and Sanga. From there, you try to beat your opponent down with giant boss monsters that always float backwards to their more basic forms. Once you got the big three in rotation in the banished pile, GY and field, you have a good grind game to beat your opponent down with.
There are no supplemental engines with this version of the deck, so I tried to stuff in as many staples as possible so the deck can play in it's "pure" form.
GLHF Duelists, and Happy New Year! May we have another amazing year of Yugioh!