This set takes advantage of Gothita's spectacular movepool by turning it into a special powerhouse. The objective of this set is to deal as much damage as possible before Gothita faints, and Life Orb helps it do just that. With a lucky base HP stat that allows it to lower its HP to 19, the magic Life Orb number, Gothita is capable of attacking 19 times before it faints, assuming no other damage is taken. The most unique thing about Gothita, however, is its stat distribution. Gothita possesses good Special Attack, Speed, and bulk, allowing it to switch into neutral hits and still hit hard. Unlike Abra, Solosis, and other frail Psychic-types, Gothita isn't afraid of most priority attacks, and it can even survive most super effective special hits. Typing and stats aren't all that makes Gothita a good attacker, however. While most Life Orb attackers have to be very wary of an opponent that is potentially threatening, Gothita's special trait, Frisk, allows it to scout the opponent's item. This can be crucial against opponents that may or may not be threatening depending on their item, such as Gastly and Chinchou.
In the first slot, you have the choice of Psychic or Psyshock. Psychic is usually the superior choice due to its higher Base Power, but Psyshock's effect of hitting the opponent's Defense stat can be useful on specially defensive Pokemon such as Munchlax. Another tough choice is choosing between Thunderbolt and Hidden Power Fighting. Thunderbolt will be of more benefit in most situations, but Hidden Power Fighting allows Gothita to hit Dark-types such as Pawniard that lack Sucker Punch. Hidden Power Fighting also leaves Gothita with a secret weapon against Ferroseed, which will almost always try to set up on it. Substitute or Calm Mind is up to how you want to play Gothita. If you want to use Gothita more strategically to beat a certain Pokemon, Substitute is the way to go. If you just want to use it as a powerhouse, Calm Mind will help you more.
Energy Ball hits a few things harder than Thunderbolt, namely Hippopotas, Wooper, and Chinchou. Thunderbolt does, however, have higher Base Power and will hit most Water-types harder, so it's a better choice in the second slot. Hidden Power Fire is another option in the second slot if you want to hit Ferroseed or Bronzor harder, but that's the sole advantage it offers over Hidden Power Fighting.
Gothita's Special Attack isn't high enough to net the many KOs that people would like, so entry hazards can be used to remedy this issue. Stealth Rock and Spikes are both prime choices for entry hazards. Toxic Spikes also helps, but won't really do anything unless Gothita runs Substitute to stall out its opponent's health. It may seem like a strange idea, but using a fast Grass-type such as Cottonee to provide Leech Seed support will help Gothita a lot. Life Orb recoil can be the difference between Gothita living or not, and Leech Seed will essentially negate the recoil, and then some.