Moves
U-turn is strong tool for gaining momentum, pivoting out against faster Pokemon or unfavorable switch-ins like Regirock and Aggron. Rest is Type: Null's main form of recovery and can also cure all status ailments at the cost of falling asleep for a few turns. Sleep Talk lets Type: Null act while it is asleep, potentially letting it pivot out of Pokemon that try to take advantage of its status, allowing it to not be as passive.
Set Details
Eviolite further increases Type: Null's defenses, allowing it to do its job defensively. 8 Defense EVs make for an even number that gives it two extra points thanks to the Eviolite boost. Battle Armor is great for making Type: Null more reliable as a wall, preventing critical hits from attackers.
Usage Tips
Type: Null should pivot into strong special attackers and users of status-inducing moves like Jynx, Lanturn, Swanna, and Altaria. Beyond that, generating momentum is Type: Null's other key role; U-turn is safe to use on predicted switches to avoid unfavorable matchups against either bulky Pokemon like Regirock and Qwilfish or Fighting-types that comfortably take Return like Gurdurr. From there, it should use that opportunity to get in wallbreakers or Pokemon that can threaten them out. In other cases, Return can be nice for consistent damage when not a lot of Pokemon that resist it are left. Using Rest when Type: Null is weakened is important to keep it healthy to check special attackers, force switches, and pivot around as much as it can. When asleep, finding opportunities to burn sleep turns is recommended, which can be done against the large number of Pokemon that Type: Null is not significantly damaged by. It is often able to safely use Sleep Talk without being too passive, as it can sometimes pivot out with U-turn. Lastly, Type: Null should be wary of foes with Knock Off or Trick and should play around users Taunt sparingly, as they can punish attempts to use Rest.
Team Options
Type: Null's ability to blanket check special attackers and reliably pivot around allows it to support offensive and defensive teams alike. Wallbreakers such as Absol, Omastar, and Aurorus that appreciate safe switches are solid options, as they can take advantage of Ghost-types like Oricorio-G and Spiritomb. Fighting-type checks are top priority, which include Pokemon like Qwilfish and Scyther; Qwilfish can set up Spikes to chip down said Fighting-types, and Scyther appreciates Type: Null's ability to absorb status and can form a strong pivoting core alongside it. Pursuit trappers such as Skuntank and Spiritomb can help remove problematic Ghost-types especially the likes of Haunter and Oricorio-G. Other strong checks to Oricorio-G include Alolan Sandslash, Oricorio-E, and Lycanroc, which all appreciate Type: Null bringing them in safely with U-turn to apply offensive pressure on their own. Type: Null pairs well with other pivoting cores that can include Primeape, Lanturn, and Eelektross, all of which can use their own offensive typing, utility, and strong attacking moves to force switches. Physically defensive Pokemon like Tangela, Regirock, and Gurdurr form good defensive cores with Type: Null, as they can cushion hits from physical breakers like Aggron and Stoutland better. Entry hazard removers like Skuntank, Swanna, Rotom-F are solid, since Type: Null is a pivot that is vulnerable to Spikes and every other hazard. They can also threaten Qwilfish, which Type: Null often invites in for free, as well as support Type: Null in other ways, including Skuntank's Pursuit support, Swanna's STAB combination and special attacking prowess that lets it pressure Rock- and Fighting-types like Regirock, Aggron, and Hitmonchan, and Rotom-F's pivoting with its own Volt Switch. Pokemon that switch into Knock Off easily alleviate pressure for Type: Null; options include Rocky Helmet Oricorio-E, Silvally-Fairy, and Skuntank, which all pressure common Knock Off users like Gurdurr and Absol. Silvally-Fairy is also immune to Trick and Switcheroo, which can be useful for pivoting in certain instances.