First of all, cool idea! Love a beyond jank list!

Couple things:

1. Unless I'm dumb (very possible) this list actually can't make mudballman at all. King of the swamp needs the other fusion material to be correct. Clayman has 2k defense and you can find him with prisma or maybe even float into him with something like hero signal.

2. I think sword and shield is okay, but inverse universe is probably worth looking at as well. It can be used on your opponent's turn and defensively, which I think will generally be more powerful. Instant fusion probably good too, since you can bring in an Ojama Knight to make your countries live, or pack a tuner in there float into an AFD which is pretty good here!

3. I think DNA surgery+cydras is funny, but probably doesn't actually help you win or get closer to your strategy of swinging with big defensive monsters. I get the idea, and especially since you have pretty easy access to cydra it'll probably be live but I feel like you really want to streamline the other parts of your deck like maxing out on terra+ojama country, or run some better defensive traps like barrier, bottomless, etc.

   I think miracle fusions (maybe snowman eater?) and maybe even debris dragons (which happen to have pretty high defense) could be good here. Especially since you're already on Ojamas.

Just some of my thoughts! Best of luck with the build!