TL;DR
Spirit should’ve been Summoner/Support.
Magic should’ve been adjusted to punish CQC, opposite of Strength.
Strength should’ve been tankier to withstand CQC.
Weapons shouldn’t have existed, should’ve been a tool to assist the other three builds.
Disclaimers
I am not a decent writer; please do question if there are any questions
All stat builds are seen at a 1st awakening standpoint.
Pure
Mage
Works virtually identical to Arcane Odyssey’s current implementation, except it should be by nature more fragile against CQC to prevent Mage users from getting close and spamming abilities.
Berserker
Should be tankier in the sense they have more resistance against ranged attacks, should be seen as a rushing stat build that favours CQC and overwhelms the user, especially if they are Mage.
Some may think this is a clear winner against Mage, however you have to realize that Mage would be better at range, and hence can prevent the Berserker user from approaching, but if they do allow the Berserker to approach, then they should be justifiably punished.
Oracle
Should be completely reworked for a Support/Summoner orientated playstyle.
For the support, you could apply buffs to your teammates and debuffs to the enemies, instead of being pure damage, it’d assist DPS teammates in dealing more damage towards the enemy.
It’d be downright awful in a solo-play, but that’s where the summoner side shines;
You’d be able to summon a wide range of creatures, be it Bear, Boar, Wolf, basically the signature animals of a Druid in most ARPG games.
These summons would be able to deal damage and/or deal effects based on which you summoned, Bear could be DPS orientated, Boar a mix, wolf being speed, et cetera.
The support side could then apply buffs to these summons just as if they are a normal player.
still a bit iffy on the animal summoning, perhaps a “warrior” summoner would be better, like summoning Viking[1], Juggernaut[2], et cetera.
Weapon

It should be REMOVED as a stat in its totality.
Weapons in themselves seem as a strange addition to the three other stat builds.
Rather, weapons in themselves would assist each other stat build, Arcanium weapons/tools would exist to benefit Mages and its sub classes, Cestus weapons for Berserker and its subclasses, and Relics for Oracle and its subclasses.
Mage’s Arcanium would basically be a mediator for their spells and for casting them, a wand could allow for faster casting at the cost of projectile speed and size, a staff could do the opposite, slower casting for higher size and damage.
Berserker’s Cestus would work very similarly to Mage’s Arcanium by being the mediator in most of their attacks, but it would too apply special effects on direct hit with an enemy. A spiky ball on your hands would allow Berserkers to deal bleeding, but only on direct hit due to it not really making sense otherwise.
Oracle’s Relics would be changed in a manner that allows for said Relic to change the support/summoner functionality, eagle’s patrimony could allow for globally more speed, Tidestone could allow for more size, Ember Staff would allow for more damage[3], with all of the relics retaining their synergies.
Hybrid
Warlock
“Allows the user to imbue their magic into their fighting style, and vice versa for fighting style into magic.”
It stays as it currently is, allowing Strength users to apply status effects on hit.
With the addition of allowing fighting styles to be applied to magics, like how current Spirit can be infused with Magic.
Fighting Style imbuement would allow for the magics to apply status effects reminiscent of fighting styles, e.g. Bleeding and Fire with Iron Leg imbued Fire Magic.
This would too allow for the exclusive Steam magic to be used if you imbue a hot/cold magic with a cold/hot fighting style respectively.
Paladin
“Allows the user to imbue their magic into their summons, and vice versa for summons into magic.”
Magic → Summon: Grants status effect, synergies and stats of imbued magic, favouring their visual design to towards magic.
Summon → Magic: Allows the summon’s stats to be averaged with the magic, so if you imbue a strong summon onto your magic, you’d of course have on average higher damage, but you’d suffer in both speed and size.
Juggernaut
“Allows the user to imbue their fighting style into their summons, and vice versa for summons into fighting style.”
Fighting Style → Summon: Grants status effect, synergies and stats of imbued fighting style, favouring their visual design to towards fighting style.
Summon → Fighting Style: Allows the summon’s stats to be averaged with the fighting style, so if you imbue a strong summon onto your fighting style, you’d of course have on average higher damage, but you’d suffer in both speed and size.
Savant
I got nothing on this one, just works like how the present Savant works.
Annoyances.
It’s so strange that Spirit/Strength is called Juggernaut when it has nothing to do with the word juggernaut, it is neither huge, powerful, nor overwhelming, and especially not heavy.
I hate writing “fighting style” over and over, it’s such a strange thing to have when every other thing is called Magic and Summon[4], Just rename it to Style.

