Dusknoir

With its pure Ghost typing blocking Rapid Spin, high base 135 defenses, and decent Attack stat, Dusknoir has potential to be a great defensive Pokemon. However, it is completely outclassed by Rotom-A as a defensive Pokemon and spinblocker. Although it has superior defensive stats, Dusknoir suffers from a lack of useful resistances. Above all, Dusknoir has a crippling vulnerability to all entry hazards, which is worsened by its lack of reliable recovery. Rotom-A and more offensive spinblocker Gengar lack reliable recovery too, but they critically are immune to Spikes and Toxic Spikes. This hazards vulnerability means Dusknoir will be quickly worn down and unable to do its job consistently. Dusknoir is also plagued by an awful Speed stat, forcing it to take a hit first before retaliating. These attributes leave it much more vulnerable to offensive pressure than both Rotom-A and Gengar, particularly when facing Tyranitar and Jirachi, premier Pokemon in DPP OU. Dusknoir could try to scrounge up a niche with its good physical coverage and priority, which allow it to damage Tyranitar, Jirachi, and Forretress super effectively without relying on the inaccurate Focus Blast or status with Will-O-Wisp. Such traits, however, generally are not enough to make it worth using in DPP OU.