While Galvantula didn't receive an amazing ability or buffed base stats in the transition to XY, its newfound access to the near-exclusive Sticky Web has finally given it a niche in OU. Being able to effectively neuter fast, deadly threats such as Mega Lucario, Terrakion, Garchomp, and the omnipresent Genesect in a single turn is a huge boon for nearly any team archetype, and as a bonus, Galvantula doesn't fear Magic Bounce as all of its users are destroyed by its dual STAB.
Unfortunately, Galvantula, as well as Sticky Web itself, has some severe limitations that prevent it from being a shoe-in for every team. With the re-introduction of Excadrill to OU and the new Defog mechanics, entry hazards are easier than ever to remove, which is a major problem for Galvantula as its frailty prevents it from reliably setting up Sticky Web more than once a match. Sticky Web also suffers from its inability to affect Flying or Levitating opponents; common Pokemon such as Rotom-W, Thundurus, Talonflame, Latios, and Latias remain unfazed and can carry out their normal duties without interruption, which leaves a lot of Sticky Web's (and thus Galvantula's) utility up to team match-up.
name: Sticky Web
move 1: Sticky Web
move 2: Thunder
move 3: Bug Buzz
move 4: Hidden Power Ice
ability: Compound Eyes
item: Focus Sash
evs: 252 SpA / 4 SpD / 252 Spe
Sticky Web is the reason to run Galvantula. It provides massive team support at the cost of only a single turn and instantly provides your team with a huge advantage over the opponent as long it remains active. Thunder combines well with Compound Eyes, reaching a much more reliable 91% accuracy, and helping to make up for Galvantula's mediocre Special Attack with its high Base Power. Thunder provides valuable coverage against Xatu, Starmie, Tentacruel, and Mega Blastoise, which might try to reflect or remove Sticky Web. The high paralysis rate is also generally handy against fast offensive Pokemon that aren't weak to it, such as Terrakion and Genesect, potentially crippling them if they stay in to attack Galvantula. Bug Buzz dissuades Latios and Latias from attempting to use Defog on Galvantula, and also makes short work of Espeon and Mega Absol. Hidden Power Ice provides valuable coverage against Landorus-T, Gliscor, and Garchomp, and is also Galvantula's best way to deal damage to Thundurus-T, which could otherwise use Galvantula as setup fodder. Volt Switch is also an option in the last slot to preserve momentum after Galvantula sets up Sticky Web, although at the cost of greatly limiting its coverage. Hidden Power Fire is also an option in the final slot to 2HKO Excadrill, Scizor, Ferrothorn, and Forretress, and to OHKO Genesect. However, Galvantula needs a Life Orb to secure the 2HKO on Excadrill and the OHKO on Naive Genesect.
As Galvantula's defenses are beyond salvageable, this set invests solely in Speed and Special Attack to provide as much offensive presence as possible while still Speed tying with other base 108 Speed Pokemon, most notably lead Terrakion. The 4 remaining EVs are placed in Special Defense to prevent Genesect from gaining a Special Attack boost from Download. Focus Sash is generally the best item choice as it nearly guarantees that Galvantula will be able to set up Sticky Web in the lead position. However, Life Orb is an option to give Galvantula a secondary role as a speedy, decently powerful attacker and to secure the KOs mentioned earlier.
Sticky Web should be set up as early as possible. As Galvantula has little defensive synergy and very few switch-in opportunities, it should usually lead or be brought in early-game with U-turn or Volt Switch. Galvantula doesn't require much in the way of complex strategy: set up Sticky Web and then do a little bit of damage or Volt Switch away, depending on the match-up. If the opposing team has an obvious Defog user, it's best to not sacrifice Galvantula right away, as its high Speed might give it the opportunity to set up Sticky Web again. It's also best not to immediately set Sticky Web against teams that carry Bisharp, as the Speed drop will double Bisharp's attack every time it switches in.
Powerful Pokemon with no way to boost their Speed, especially Mega Pokemon, are perfect partners to capitalize off of Galvantula's Sticky Web. Mega Lucario, Mega Charizard Y, Mega Pinsir, and Mega Garchomp are great examples of Pokemon that really shine with Sticky Web support. Sticky Web also allows Pokemon that gain Speed upon Mega Evolving to outspeed more threats before they do so. In particular, Sticky Web has good synergy with slow, bulky boosters that fail to outspeed Choice Scarf users at +1, such as Dragonite and Gyarados, as it prevents their sweeps from being cut short by the likes of Choice Scarf Genesect and Terrakion. Swords Dance Bisharp also pairs well with Sticky Web as it becomes much less reliant on Sucker Punch and its mere presence on a team discourages Defog, as the Evasion drop will double its Attack due to its ability, Defiant. Powerful Choice Band and Choice Specs users form the final group of Pokemon that appreciate Sticky Web support. Notably, Choice Band Tyranitar and Choice Specs Sylveon particularly capitalize off of Sticky Web as Flying-type and Levitating Pokemon that don't fear the hazard have difficulty damaging either of them.
In the case that Galvantula is not used as a lead or manages to preserve its Focus Sash, Rapid Spin support from the likes of Excadrill and Mega Blastoise is useful to mitigate Galvantula's own weakness to hazards. Galvantula also pairs well with spinblockers; Gourgeist-H and Trevenant in particular are notable as they can reliably take on Excadrill, though Trevenant risks being overpowered by more offensive sets.
Energy Ball and Giga Drain can be used to hit Rotom-W and Mamoswine for super effective damage, but they don't hit any other common threats in OU harder than Galvantula's STAB moves. Thief is an option to steal an opponents item after Galvantula uses its Focus Sash, but Galvantula is usually better off attacking or switching out. Galvantula can also run typical Choice or all-out attacker sets, but they're outclassed by many other Electric-type Pokemon, such as Thundurus, Thundurus-T, and Mega Manectric.
Checks & Counters
**Special Walls**: Galvantula itself can't break through anything particularly bulky that isn't weak to its STAB moves, but the real threat is Sticky Web.
**Hazard Removal**: Bulky Defog users such as Latias and Scizor can easily remove Sticky Web if given the opportunity, and Excadrill can take any hit from Galvantula itself bar the rare Hidden Power Fire and Rapid Spin away Sticky Web with ease.
**Taunt**: Fast Taunt users can prevent Galvantula from setting up Sticky Web. Most notably, Thundurus can taunt Galvantula, live any hit, and then Volt Switch to break Galvantula's Focus Sash and bring in a counter to finish Galvantula off. Deoxy-S can also Taunt Galvantula to prevent Sticky Web from going up on turn one, but in the process is limited to one layer of hazards if Galvantula immediately attacks it, and possibly even none if Thunder's 30% paralysis chance comes through. Terrakion risks a Speed tie but can also Taunt Galvantula and proceed to set up Stealth Rock.