Description
Reuniclus was one of the better Pokemon to be introduced in 5th generation, and is likely the best Trick Room user in the entire game (though I still prefer Musharna because it gets Telepathy which is great for Double and Triple Battles). With its combination of decent bulk and massive Special Attack, Reuniclus is a force to be reckoned with. Its base 30 Speed would generally be crippling, but when combined with Trick Room leads to Reuniclus becoming the fastest blob of cells around. In fact, there really isn't anything out there that is slower than Reuniclus, besides other amorphous globules and the spiky monstrosity that is Ferrothorn. Otherwise, Reuniclus is unmatched in its tortoiselike crawling which cannot be overcome. Of course, it can also perform well under other sets, such as Calm Mind, and focus more on its decent defenses and great HP. In any case, Reuniclus is a powerful presence in competitive battling and should be prepared for in some way.
Reuniclus is a solid option as an offensive Trick Room setter, sporting both a Spore immunity (Overcoat) and the ability to OHKO Amoonguss. Being capable of hitting most of the metagame, Reuniclus's powerful Psychic + Fighting coverage lets it shine where other passive Trick Room setters cannot, giving it the capability to take full advantage of the speed control provided by Trick Room. However, Reuniclus is also frail, leaving it vulnerable without proper support and positioning. In addition, its vulnerability to common priority attacks such as Sucker Punch and Talonflame's Brave Bird can leave it rather susceptible to losing momentum even after setting Trick Room. It also lacks the defensive capabilities and Ground immunity offered by other options such as Cresselia and Telepathy Musharna, and it is susceptible to being walled by Aegislash, which is a common check against Trick Room teams.
Here’s my Reuniclus's summary.
Nature: Quiet
Held Item: Mental Herb
Ability: Magic Guard or Overcoat
EVs: 172 HP / 28 Def / 252 SpA / 56 SpD
-Psyshock / Psychic
-Shadow Ball
-Trick Room
-Recover
Psyshock or Psychic hits most threats neutrally besides Steel- and Dark-types and has a good chance to OHKO standard Amoonguss (you can use either one, it ultimately depends on what you opponent is running and whether you should target their physical or special defense). Shadow Ball is a good option for covering Aegislash and is guaranteed to break Substitutes from Steel-types like Heatran and Mawile. Trick Room allows slower Pokemon to take advantage of the reversed move order and put the opponent on the defensive for four turns. Recover is necessary for continually recovering Reuniclus's HP while it is setting up and after it switches in on Pokemon such as Mega Lopunny or Dragalge.
Maximum Special Attack EVs with a Quiet Nature enable Reuniclus to maximize its damage output. Minimizing Speed allows Reuniclus to get valuable Speed ties with Amoonguss, KOing it before it can put Reuniclus's partner to sleep, and also allowing Reuniclus to underspeed most things in the metagame. The distribution of the remaining EVs between HP, Special Defense, and Defense maximizes Reuniclus's bulk in the most efficient way possible, letting it survive Aegislash's Shadow Ball and giving it an extremely high chance of surviving Mega Kangaskhan's Sucker Punch, though only from full health. Mental Herb is the preferred item as you want to get Trick Room up as soon as you can (which is impossible to do if you're taunted. Setting up Trick Room is usually vital for Reuniclus because while it does not become dead weight offensively even after being Taunted, since it is still able to deal heavy damage thanks to its high Special Attack stat, it'll still be very slow moving and the opponent can then easily KO it.
Of course Reuniclus can run a variety of other moves. Here are some suggestions:
-Focus Blast lets Reuniclus hit those Steel- and Dark-types for super effective damage. But keep in mind that it has low accuracy.
-Reuniclus can use Focus Sash or Mental Herb if it wants to sacrifice damage output for an easier time setting up Trick Room.
-In addition, Life Orb is another option and can be good to increase Reuniclus's damage output, which drops significantly if one runs Focus Sash.
-Helping Hand can be useful for when you foresee an incoming Fake Out, as it has higher priority.
-For abilities, Regenerator is an interesting option that enables Reuniclus to restore its HP after taking a hit, giving it good staying power, but Overcoat's Spore immunity is incredibly valuable for a Trick Room team. Regenerator can fit on Reuniclus when it is used on semi-Trick Room teams rather than full Trick Room. Colbur Berry is an option that lets Reuniclus tank Dark-type hits better.
-The advent of Z-Moves gives Reuniclus some interesting options that help handle particular threats such as running either Energy Ball or Grass Knot and Grassium-Z for Quagsire and Electrium Z + Thunder to handle Pyukumuku. Gigavolt Havoc also has the benefit of blowing through Tapu Fini and certain Steel-types, such as Celesteela.
Notes:
I didn't nickname my Reuniclus at first, but later I ended up nicknaming it after Peridot from Steven Universe. Both are green and have tiny bodies. What's more is that both have telekinetic abilities (even though Peridot is restricted to only being able to telekinetically control metal).
Do you have your own Reuniclus moveset and strategy? Comment below with your moveset!