I built an orcust deck in master duel again, this list aims to optimize your endboard but in return you play a lot of garnets.
As for Thunder dragons, you equip Dragonroar with union carries, Dragonroar summons dragondark when the monster it’s equipped to goes bye then dragondark adds dragonhawk and in turn resummons dragondark and meet the conditions for summoning colossus.
Just go with what will give you the most interruptions and you’ll be just fine.
Yeah, that’s about all I got! Hope you enjoy!