i dont think you need 2 dimension fusion and 2 returns, just 1 of each would do. then take out the 2 fissure and add another smashing ground and 2 creature swaps i guees, and then another sakuretsu armor for 1 of the returns.

drop both dimesion fusions (mainly because your oppenant can bring stuff back too) and add in some threaten roars (you can activate in in repose to mobius, mst, storm, tornado and you are able to save slate and geaf).

since you are running two necrofears the giant germs allow to get lp damage to your oppenant and they fill out the graveyard for necro fear. the newdoria's are nice but then you would want to add in some mystic tomatos so get them out faster. that would mean taking out some slates and geaf.

it is a better version of wabaku. it is a normal trap that says your opponent can't conduct their battle phase. so it will save your slates and geaf from ddwl or something else that could smash in to it and do some harm.

im not really sure what else to say but creature swaps work well in fiend decks. give em newdorias, tomatos, germs, sangan, and all that stuff. But you dont even have to have monsters like that in a deck to run creature swap. I faced this guy used was using a warrior staple deck who used creature swap so skilled-ly on my @$$. Try taking out dimension fusions for them and see how they work.