Despite what legions of 4chan users may say, Lopunny is not so hot on the battlefield. Normal typing, middling bulk, and non-existent offenses severely hold Lopunny back. However, she has a single niche in the combination of Klutz and Switcheroo, which allows Lopunny to carry disruptive items without any repercussion, and give it to the opponent to cause problems. This, combined with her access to niche moves such as Encore, Baton Pass, and Healing Wish, means that Lopunny can be a surprisingly effective supporter for an offensive team. Her movepool is laced with niche and situational options that require much prediction, but Lopunny is the type of Pokemon that pays off if used correctly.
Switcheroo is Lopunny's greatest niche, and the ability to give Choice Scarf to a defensive Pokemon and Pokemon that rely on Eviolite without suffering its downside should be the sole reason for using Lopunny. Encore, while somewhat redundant with Switcheroo and Choice Scarf, allows Lopunny to be a continual nuisance even after it gives away its item. Not to mention, Lopunny can switch in on a set-up move and Encore, giving your team momentum. The remaining two slots are very much dependent on the team, as Lopunny has myriad of options, and listing them would simply not be very efficient. Thunder Wave fares well against offensive teams, crippling opposing Choice Scarf users expecting to receive Switcheroo. Healing Wish provides cleric support for an offensive team, but leaves Lopunny without an attack. On the other hand, Return allows Lopunny to deal damage when needed, but is ridiculously weak.Team Options & Additional Comments >>>
Lopunny is quite the mix-and-match Pokemon. In fact, combining any four moves on the main set or in the AC will make for a decent set if those moves fill a specific purpose on your team. Lopunny's ability to cripple Pokemon in a blink of an eye means that it can pull off a good Baton Pass set. However, the presence of Volbeat, Ninjask, and other premier Baton Passers in NU means that Lopunny will often be outclassed in such a role. Still, the Substitute + Baton Pass set is unique in that it can easily cripple two Pokemon and pass a Substitute, and thus it is very much a viable option. While Ninjask may outclass such a set in a dedicated Baton Pass team, Lopunny fares better in an offensive team that has the option of Baton Passing for greater set-up opportunity.
As a Normal-type, Lopunny has multiple options that are simply not viable. In general, offensive Lopunny will find itself outclassed by multiple Pokemon. She has a great special movepool, but Special Attack is indeed her lowest stat, making a special set a futile attempt. A physical attacker set is overshadowed by Kangaskhan, who boasts the same access to Fake Out, Drain Punch, and Circle Throw. Limber is available as an alternative ability from Dream World, but it takes away her only true niche as a supporter. Other support moves such as Rain Dance, Sunny Day, Entrainment, and Charm can work, but there are better weather setters in NU, and the remaining options are too situational.
Checks and Counters
As a general rule of thumb, if something doesn't mind a Choice Scarf, it is incredibly vulnerable to Thunder Wave. For example, offensive Fire-types, such as Charizard, do not mind Flame Orb / Choice Scarf, but hate Thunder Wave. As a result, if you are forced to switch a Pokemon into Lopunny, you can be certain that it will be crippled. However, Lopunny has weak defenses, and she will rarely force a switch unless she can Encore a set-up move. Therefore, Team Preview is one of Lopunny's biggest enemies; if you see it on an opposing team, you should refrain from setting up with a slower Pokemon. Otherwise, Lopunny should fall to one or two strong STAB attacks.
However, there are few Pokemon that are partially immune to Lopunny's bag of crippling status moves. In general, Ground-type special attackers do not mind Lopunny's status setting role. Camerupt is immune to both Thunder Wave and Flame Orb, and Seismitoad does not mind a Choice Scarf or a burn. Taunt users can also shut down Lopunny, but Lopunny will very often outspeed your Taunt user and cripple it as well. Faster Substitute users can also guard against status and Switcheroo, but this requires a fair amount of prediction as Lopunny can simply Encore the Substitute.