The most important part of all of this is having fun. Don't feel the need to minmax your team, or play in a way that you find tedious or boring. This guide is a bunch of recommendations, not requirements; feel free to completely change up their builds, or use other Personas entirely if you so wish.

Again, I want to note that this is meant for the late game, where you're at least level 75 or so, and you can create just about any Persona you need to.

If you don't know how fusions work, this explanation should help a lot: Persona 4 Golden Fusion Chart[gamefaqs.gamespot.com]

Null X, Repel X, and Absorb X are some of the most powerful skills in the game - they completely prevent damage dealt of that certain type, and can even return the damage to the enemy (Repel) or heal you (Absorb). Here's a quick rundown of the Personas with these skills, so you don't have to spend a lot of time searching for the one with the skill you need:

Name - Arcana and Level needed to fuse - Skill

Shiki-Ouji - Fool 56 - Null Physical
Loki - Fool 64* - Null Fire
Rangda - Magician 47 - Repel Physical
Jinn - Magician 62 - Null Physical
Surt - Magician 69 - Null Ice
Isis - Empress 79* - Absorb Ice, Null Elec
Sarasvati - Priestess 17 - Null Wind
Tzitzimitl - Priestess 70 - Repel Elec
Skadi - Empress 52 - Repel Ice, Repel Fire
Setanta - Emperor 34 - Null Fire
Okuninushi - Emperor 41 - Null Wind
Ishtar - Lovers 71* - Absorb Wind
Thor - Chariot 65 - Null Physical
Uriel - Justice 58 - Null Dark
Nebiros - Hermit 63 - Null Light
Arahabaki - Hermit 73 - Repel Physical
Lachesis - Fortune 51 - Absorb Wind
Orthrus - Hanged Man 39 - Null Ice
Taown - Hanged Man 56 - Absorb Fire
Hell Biker - Hanged Man 66 - Absorb Fire
Yurlungur - Temperance 69 - Repel Light
Abaddon - Tower 55 - Null Physical
Mara - Tower 62 - Absorb Physical
Yosh!tsune - Tower 75 - Repel Elec
Garuda - Star 57 - Repel Wind
Helel - Star 87* - Repel Wind
Girimehkala - Moon 48 - Repel Physical
Seth - Moon 68 - Null Light
Sandalphon - Moon 84* - Repel Dark
Jatayu - Sun 61 - Repel Electric
Horus - Sun 68 - Absorb Wind
Kushinada-Hime - Aeon 44 - Null Fire
Laksmi - Aeon 65* - Null Dark
Michael - Judgement 72 - Repel Dark
Satan - Judgement 76 - Null Wind
Metatron - Judgement 83 - Repel Ice, Repel Elec, Repel Fire
Ardha - Judgement 90 - Null Physical
Lucifer - Judgement 93* - Absorb Electric, Repel Light

* means that max social link is required

NOTE: Null or Absorb are recommended over Repel (besides Light and Dark, of course) due to enemies having Absorb resistances, and the reflected damage could possibly heal them. The only Repel I tend to use is Electric, since it's the only Electric nullification from level 61 until level 79, plus the need for a maxed out Empress link.

NOTE 2: Fusion is recommended over skill cards due to the rarity of Absorb skill cards (the only choice, since Null and Repel skill cards don't exist, for whatever reason), and due to how expensive the cards are (at a whopping 300,000 yen).

I also recommend having a few personas that you stack resistances onto so fusing is easier (ie; you put every Null/Absorb possible on to a Jinn and Mara, so anything that can be fused with a Tower or Magician persona can easily access the resistance abilities).

First off, there are 4 Personas with the strongest elemental spells in the game (and are the only personas able to learn those spells). They're pretty much the go-tos for certain elements. They aren't required, but they certainly help.

Universal skills, so I don't have to explain them more than once:
Mind Charge - Increases the damage of the user's next spell by 250%. Required for almost any dedicated mage. Feel free to change this out for an extra resistance if you have a support persona that can cast it instead.
Elemental Amp/Boost - Amp and Boost increase the damage of elemental spells of the designated type by 50% and 25% respectively, making them essential for personas focusing on a single elemental type.

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Loki - Fool 64 (also requires the Fool Social Link to be maxed, which happens automatically)

Loki is the go-to Ice Persona, and is the only persona that can learn Niflheim, which deals severe Ice damage to one enemy. He learns Null Fire naturally.

Recommended Build:

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Surt - Magician 69

Surt is the go-to Fire Persona, and is the only persona that can learn Ragnarok, which deals severe Fire damage to one enemy.

Recommended Build:
*can also be replaced by Null/Absorb Physical or Null/Repel Electric

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Thor - Chariot 65

Thor is the go-to Electric Persona, and is the only persona that can learn Thunder Reign, which deals severe Electric damage to one enemy. Thor learns Null Physical naturally.

Recommended Build:
*can also be replaced by Null/Repel Dark

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Odin - Emperor 74 (also requires the Emperor Social Link to be maxed)

Odin is the go-to Wind Persona, and is the only persona that can learn Panta Rhei, which deals severe Wind damage to one enemy.

Recommended Build:
*can also be replaced by Null/Absorb Physical or Null/Absorb Ice

Daisoujou and Alice are the most powerful Hama and Mudo casters in the game. While useless in boss battles, they really help in quickly wiping out regular mobs, making getting through dungeons much less of a pain.

Daisoujou - Hierophant 60

Saisoujou is the best Hama caster in the game, having access to Samsara (kills enemies without Light resistance). Since he only needs two skills to be effective (Samsara and Hama Boost), you can fill the rest of the slots with either resistances or support skills.

Recommended Build:

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Alice - Death 72 (also requires the Death Social link to be maxed)
Can only be fused by using Belial and Nebiros

On the other end, Alice is the best Mudo user in the game. Die for Me! is the dark counterpart of Samsara, and she's used for pretty much the same purpose as Daisoujou. You could use Alice for support as well, but Daisoujou and a dedicated support persona should be covering those bases instead. I prefer to make her an unkillable wall instead.

Recommended Build:

Trumpeter - Judgement 67 (Can only be created through Hexagonal Fusion)

Ah, Trumpeter. Considered to be one of the best, if not the best, support persona in the game, due to all of its natural resistances and Debilitate, which helps take bosses down a peg. Stick the support abilities you like onto him and go wild.

Recommended Build:

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Beelzebub - Devil 81 (requires the Devil Social Link to be maxed, and can only be created through Hexagonal Fusion)

Beelzebub is tied with Trumpeter for most natural resistances, which gives him a lot of flexibility. While he's probably most fitted to be a support persona, feel free to go wild with what you want him to be. Experiment, try out new moves and combinations, have fun with it.

Recommended Build:

WIP

Helel - Star 87 (also requires the Star Social Link to be maxed)

WIP. (Summary: Morning Star hits like a truck.)

Recommended Build:
*can be replaced by God's Hand and Arms Master, maybe Ma- elemental skills

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Yosh!tsune - Tower 75

WIP. (All you need to know is that this is hands down one of the strongest persona in the game. Hassou Tobi is stupidly strong.)

Recommended Build:
*Pretty much a free spot. There are several good skills you could put here: Auto-Mataru, Apt Pupil, and Debilitate are some choices.

Empty, because I've yet to publish this.

If there's anything I missed, or any personas or builds of your own you'd like to add, feel free to comment below. I'm quite excited to see the sorts of personas people have created.

Thank you for reading, and stay safe.