Moves
Will-O-Wisp is important for crippling physical attackers while also adding on residual damage. Synthesis keeps Gourgeist-XL healthy, though be wary of hail and rain, which cut its recovery to a mere 25%. Foul Play is Gourgeist-XL's main attack, allowing it to hit setup sweepers such as Barbaracle, Swords Dance Samurott, Klinklang, and Torterra for a lot of damage. Seed Bomb is a usable option over Foul Play to deal with Water- and Ground-types, such as Omastar, Kabutops, and Rhydon, much more quickly. Leech Seed allows Gourgeist-XL to gain a small amount of recovery while putting pressure on switch-ins, as well as hindering bulky setup sweepers such as Musharna. It also allows Gourgeist-XL to rely less on Synthesis for recovery, which is especially handy if it runs a Colbur Berry. Rock Slide is a neat option for hitting Fire-, Flying-, and Ice-types, such as Charizard, Pyroar, Magmortar, Swellow, and Abomasnow, that usually want to switch into Gourgeist-XL, preventing it for being setup fodder for them. Skill Swap is a very interesting tool against setup sweepers, as it can rob Hariyama's Guts or pass on Insomnia onto RestTalk Pokemon such as Malamar and Mega Audino. It can even trip up certain switch-ins, such as Magic Bounce Xatu, Speed Boost Combusken, Scrappy Swellow, and Refrigerate Aurorus, making them easier to play around.
Set Details
Maximum HP and Defense investment with an Impish nature grants Gourgeist-XL maximum physical bulk, improving its walling capability against the tier's physical attackers without the help of Leftovers. Colbur Berry weakens super effective Dark-type moves, which allows it to shrug off hits such as Hariyama's Knock Off and tank Shiftry's Knock Off in order to get off a burn. Leftovers is an alternative if these two are sufficiently covered. Frisk is generally the most useful ability, as it allows Gourgeist-XL to scout the foe's item, most notably identifying if the foe is wielding a Choice item or not. If you're using Skill Swap, Insomnia is the preferred ability, as it can be used to stop RestTalk Pokemon, such as Malamar and Mega Audino.
Usage Tips
Gourgeist-XL has an easy time switching into physical Fighting-, Ground-, and Water-types, such as Hitmonchan, Rhydon, Samurott, and Barbaracle. Its main objective is to burn foes and keep itself healthy. However, it should be cautious about throwing out Will-O-Wisp to avoid giving free switches to certain Pokemon, such as Fire-types and especially Xatu, so it would be wise to either make double switches or try to hit them on the switch with an effective move. Gourgeist-XL can use its last attack to target switch-ins, usually consisting of special attackers that are weak to Rock, rely on their ability, or dislike getting their health worn down.
Team Options
Gourgeist-XL mainly fits on more passive and defensive teams, although it can also find its place on more balanced teams. Pokemon that resist Gourgeist-XL's weaknesses, primarily Fire, Ice, and Ghost, make for good teammates. Lanturn, Thick Fat Hariyama, and Assault Vest Magmortar resist Fire and Ice, but the former two share a Freeze-Dry and Flying weakness, respectively, with Gourgeist-XL, which should be covered with other teammates. Mega Audino and Skuntank can handle Gourgeist-XL's Ghost and Dark weaknesses, with the former providing Heal Bell support and the latter Pursuit trapping bothersome Ghost- and Psychic-types, notably Xatu. In return, Gourgeist-XL can fend off the Poison-, Steel-, and Ground-types that threaten them. Mega Audino also appreciates Gourgeist-XL luring in and KOing Fire-type setup sweepers, such as Ninetales and Charizard, with Rock Slide, as they would otherwise set up easily on Mega Audino. Gourgeist-XL makes for a good teammate for the Pokemon whose weaknesses it resists; the likes of Kangaskhan, Pyroar, Rhydon, Kabutops, and Archeops like Gourgeist-XL's ability to feasibly switch into most threatening physical attacks for them.