Moves
Sludge Bomb is Naganadel's most reliable attack: a STAB move that does generally good damage and is also notably useful for hitting key threats in Tapu Fini and Tapu Bulu super effectively. Fire Blast allows Naganadel to smash Steel-types, primarily Mega Metagross but also Kartana, Mega Scizor, and Ferrothorn, which can take on Naganadel relatively unopposed otherwise. Tailwind lets Naganadel provide speed control support, helpful in keeping up the pressure its team applies, letting them outrun most foes unabated. Protect lets Naganadel defend itself, which is useful for positioning and stalling field effects; alternatively, Draco Meteor offers a secondary STAB move that provides Naganadel extra damage at a cost, hitting Kyurem-B and Ground-types like Zygarde and Landorus-T hard.
Set Details
Maximum Speed and Special Attack investment and a Timid nature are used to maximize Naganadel's offensive capability, notably also allowing it to outrun Mega Metagross and Mega Salamence. Life Orb is used in order to boost Naganadel's damage output, which is handy in getting KOs and generally pressuring threats.
Naganadel can also take a slightly different route, instead utilitizng an Assault Vest set with U-turn in place of Tailwind. This sacrifices some field conditioning ability and damage in favor of pivoting utility. Even with an Assault Vest equipped, however, Naganadel isn't particularly bulky, and if it wants to invest enough to survive relevant attacks like Life Orb Kyurem-B's Ice Beam or Choice Scarf Tapu Lele's Psychic without Terrain support, then Naganadel will have trouble getting KOs.
Usage Tips
As much as possible, Naganadel should be put in a position where it can threaten foes in an aggressive manner, as its role is to apply pressure and nothing else. In the early- to mid-game, it can be used as a way of putting instant pressure and momentum thanks to its high Speed and vast coverage. Later on, as the opposing team gets weakened, it can also be a handy way of cleaning up an opposing team. When Naganadel can't quite get the KO it needs or has done its job and is in a bad position, Tailwind is an option to fall back to; it doesn't matter if Naganadel gets KOed in the process, as this also provides a free switch, often giving you back the momentum as you get the chance to respond with the appropriate threat for free while also being considerably supported by Naganadel's last-ditch Tailwind effort. As Naganadel is quite frail and is chipped down over time by Life Orb recoil, care should be applied when it comes to its health, as it can get KOed easily; one should try to bring it in only on free switches or predicted weak hits such as Tapu Fini's Muddy Water. At times, it can be important to pay attention to Naganadel's Beast Boost ability, as it can be useful in allowing Naganadel to outrun otherwise faster key threats such as Tapu Koko, Deoxys-A, and Choice Scarf Tapu Lele; occasionally, this ability can also be nifty in allowing Naganadel to outrun opposing teams even if their Tailwind is up, so take note.
Team Options
Naganadel fits well in a team composition heavily based on applying overwhelming offensive pressure to win. With that in mind, Deoxys-A, the quintessential hyper offense Pokemon, works well with Naganadel, as it is capable of pressuring teams and handling the few unboosted threats faster than Naganadel, such as Tapu Koko and Mega Manectric, and has the coverage that lets it hit Tyranitar hard. On another note, Pokemon that generally appreciate having Tailwind support for their offensive jobs are good teammates, with generally strong attackers like Tapu Bulu, Choice Band Zygarde, and Mega Metagross all fitting the bill. Fire-type teammates are also good to have, as they can reliably punch through Steel-types, allowing Naganadel to use its STAB attacks more often; Mega Charizard Y is a good pick, as it also appreciates Naganadel's Tailwind allowing it to use its powerful sun-boosted Heat Wave more freely, while Volcanion can be nifty for also being able to threaten Tyranitar, Stakataka, and Heatran. Any checks to opposing Deoxys-A and Choice Scarf Tapu Lele are welcome additions; Steel-types such as Mega Metagross, Aegislash, and Genesect can reliably take their STAB moves quite handily and easily KO in return, while having your own Choice Scarf Tapu Lele can be useful enough in checking opposing Deoxys-A as well as other fast threats like Tapu Koko. As Naganadel is a liability in Trick Room, having teammates that can deal with the field condition are huge boons. Taunt users such as Tapu Koko and phazers such as Suicune can be handy to have for stopping Trick Room from being set up. However, if it does get set up, some handy bulky pivots such as Aegislash and Zygarde can be useful for playing around Trick Room and stalling it out. Tapu Koko, Tapu Bulu, and Tapu Lele can make good partners for Naganadel, as they can remove the Misty Terrain that weakens its Draco Meteor.