hoi. Ok, I have just been running M-Spiritomb and want to just summarize all the things I know about it, to help casual users and serious users both. Because of the huge increase in power quality and the awesome hidden ability, Spirutomb can take down nearly anything in the game with a noctem-boosted shadow sneak or suck punch. However, there are a lot of variations due to thee increased special stats and the decent defenses. you could run a physical set with 252 HP/ 252 ATK/ 6 DEF. moveset: sucker punch/ shadow sneak/rock blast or zen headBUTT/ pain split or will-o-wisp. the most effective moveset for making your opponent swear is a set with will-o-wisp and pain split, but you would have to put in pokes like ferrothorn or that steel ultrabeast to counter fricking fairy moves. ivs- 252 HP 244 DEF 8 ATK 4 SPDEF. by the way you can get will-o-wisp and pain split by berreeding with chandelure. hope i was some help.
Bulky Noctem sets almost always use Will-O-Wisp. Pain Split is great for recovery and chip damage, but Rest can be used for more sustain. For the other slots, Shadow Sneak, Pursuit, and Sucker Punch are good.