* Deoxys-D has a wide support movepool, having access to all of Knock Off to annoy potential switch-ins, an entry hazard in Spikes, and reliable recovery.
* Deoxys-D's Speed stat is not excellent but at least allows it to outspeed most other walls.
* Deoxys-D can potentially act as a check to threatening Psychic-types, such as Deoxys-A.
* Unfortunately, Deoxys-D's excellent defensive stats are undermined by its woeful HP, which detracts from its bulk and leaves it vulnerable to very powerful attacks, such as most Z-Moves.
* Deoxys-D is very passive, rendering it very susceptible to Taunt.
* Deoxys-D's Psychic typing is simply not conducive to its role as a wall, as it offers it little in the way of useful resistances, fails to protect it from entry hazards and Toxic, and shoulders it with horrible weaknesses to Ghost- and Dark-type moves, which are extremely common in Ubers. This means that it confers virtually no defensive benefit to teams.
* Due to this multitude of crippling flaws, Deoxys-D offers nothing over other defensive users of Spikes, such as Skarmory, Ferrothorn, and Klefki, all of which can check a wider variety of Pokemon and disrupt opposing teams more effectively. Do not use Deoxys-D.
move 1: Spikes
move 2: Recover
move 3: Knock Off
move 4: Toxic
evs: 252 HP / 252 Def / 4 SpD
* Spikes allows Deoxys-D to make use of free turns, punishing the opposing team by wearing down grounded Pokemon that switch in.
* Recover increases Deoxys-D's staying power. It also allows Deoxys-D to Toxic stall the few Pokemon that cannot break through it.
* Knock Off prevents Deoxys-D from being total Taunt bait, OHKOes Deoxys-A, and punishes switch-ins by removing their items.
* Toxic lets Deoxys-D cripple switch-ins, such as Giratina-O, support Arceus formes, and the plethora of offensive Pokemon that can take advantage of it, such as Yveltal.
* Taunt is also an option, as it allows Deoxys-D to prevent slower walls that it cannot touch, such as Ferrothorn, from setting up on it.
* Maximum investment in HP and Defense alongside a Bold nature maximizes Deoxys-D's physical bulk.
* Leftovers gives Deoxys-D access to passive recovery.
* Deoxys-D should be switched into Pokemon that are unable to break through it, such as specially defensive Primal Groudon, Magearna, and Zygarde-C.
* Use Deoxys-D's free turns well, as it should not be kept in play for longer than a few turns at most.
* Spikes should be set whenever it is safe to do so. Bear in mind, however, that Deoxys-D's bad matchup against most Pokemon in Ubers renders opportunities to set up Spikes infrequent.
* If it is obvious that something that can easily take advantage of Deoxys-D, such as a setup sweeper, defensive Spiker, or Defog user, is going to switch in, use the appropriate move to cripple them before switching Deoxys-D out.
* Feel free to sacrifice Deoxys-D in the event that it successfully does its job of stacking Spikes and walling threats.
* Stealth Rock users, such as Primal Groudon and Dialga, can form a hazard-stacking core with Deoxys-D.
* Pokemon that can deal with Dark-types, such as Xerneas, Arceus-Fairy, and Magearna, are useful teammates. Xerneas appreciates Deoxys-D's ability to slowly wear down its checks with Spikes.
* Arceus-Dark, Yveltal, and Darkrai can beat Ghost-types, which otherwise easily take advantage of Deoxys-D.
* Wallbreakers, such as Swords Dance Primal Groudon, Calm Mind Primal Kyogre, Zekrom, and Palkia, and sweepers, such as Mega Salamence and Mega Lucario, are greatly assisted by Spikes.
* Deoxys-D can act as a Stealth Rock user. However, Stealth Rock exacerbates Deoxys-D's already severe four-moveslot syndrome, making it a poor option.
* Magic Coat allows Deoxys-D to frustrate Pokemon that attempt to set up hazards or inflict status conditions on it. However, Magic Coat is very reliant on good prediction to succeed, which can result in dire consequences should Deoxys-D mispredict and give the opponent a free turn.
* Skill Swap allows Deoxys-D to bypass Mega Sableye. With good prediction, it can also bother switch-ins; for example, using Skill Swap on a predicted Mega Gengar switch-in allows Deoxys-D to switch out and possibly gain momentum for its team. However, it is usually not worth sacrificing a moveslot for the sole purpose of annoying a single Pokemon.
* Ice Beam lets Deoxys-D check Mega Salamence and Zygarde-C, as well as chip away at Pokemon that lack reliable recovery, such as Primal Groudon. However, it has no other use and makes Deoxys-D even less effective at supporting its team.
* Deoxys-D can run Shed Shell over Leftovers, allowing it to escape from Mega Gengar. However, this deprives Deoxys-D of important passive recovery, forcing it to rely excessively on Recover to keep healthy.
Checks and Counters
**Mega Sableye**: Mega Sableye can switch into Deoxys-D if it attempts to use Spikes or Toxic and simply deflect both moves with Magic Bounce, making Deoxys-D useless. However, Mega Sableye's usefulness as a check diminishes if Deoxys-D is running Skill Swap.
**Ghost-types**: Arceus-Ghost can either set up Swords Dance on Deoxys-D or simply OHKO it with an unboosted Never-Ending Nightmare. Mega Gengar easily traps and removes Deoxys-D; this vulnerability is magnified if Mega Gengar is carrying Taunt, as Deoxys-D becomes almost defenseless against it in this scenario and is forced to retaliate with weak Knock Offs. Aegislash 2HKOes Deoxys-D with Shadow Ball and is immune to Toxic. Lunala can either 2HKO Deoxys-D with Moongeist Beam or use it as setup fodder. Giratina-O can Defog away Deoxys-D's hazards and threaten it with a super effective Hex or Shadow Force.
**Dark-types**: Calm Mind Arceus-Dark hard counters Deoxys-D, as it can circumvent status with Refresh and laughs at its other moves. Yveltal, Alolan Muk, and Darkrai can overwhelm Deoxys-D with their super effective STAB attacks.
**Boosting Sweepers**: If Deoxys-D lacks Taunt, it becomes setup fodder for a plethora of boosting sweepers. Swords Dance Primal Groudon, Calm Mind Primal Kyogre, Mega Lucario, Geomancy Xerneas, and most Swords Dance Arceus formes, among others, can all take advantage of Deoxys-D's passivity and set up in its face.
**Taunt Users**: Faster Pokemon that carry Taunt, such as Mewtwo and Deoxys-S, prevent Deoxys-D from doing anything useful.
**Entry Hazard Setters**: If it is not carrying Taunt, Deoxys-D becomes setup bait for other Spikes users, such as Ferrothorn, Skarmory, and Klefki; these Spikes users also happen to be immune to Toxic by virtue of their Steel typing, leaving Deoxys-D useless against them.