Opportunity cost is one shitty argument. If you're running ekiller then you lose out on running cm ghostceus or sd ghostceus or support ghostceus or hail iceceus or sd dragceus, etc. So regardless of the form it still has massive opportunity costs. Not to mention we're rating mons as a whole not individual sets. SD/filler/filler/filler normal ceus is one of the sets normalceus can run it isn't normalceus itself. As for your ghostceus argument, he lacks an item bar spooky plate. Not to mention that 252+ speed statement makes no sense whatsoever. Smogon's analysis sets aren't the only sets out there. What stops normalceus from running lefties/scarf or whatnot to help cripple attackers or prolong its longevity? Nothing unlike ghostceus. So if you're really going to make an argument for ghostceus please don't use some one sided crap. Bulky arceus isn't that sturdy just fyi.