This mod is focused on integrating Ars Nouveau and Iron's Spells and Spellbooks into Mana and Artifice's mana system, and provides some balancing tweaks and QoL features that make sense to go along with it.

I think MnA makes the most sense to use as a basis because its mana bar is the most important to see due to containing other information (such as level and affinity) and also because there are different casting resources besides mana which work differently from each other. (I may be biased since it's my favorite magic mod.)

If you have any ideas or suggestions, let me know in the comments.

Mana and Artifice (Required)

Spells will instantly sync the mana bar to reality. Without this addon, there's a considerable delay.

By default, armors no longer take & repair triple damage. This can be toggled for mage armor and faction armors seperately in the server config. This is to keep mage armor competitive with the other mods' caster armors, and the fact that faction armors share this trait is confirmed to be a bug.

The decimal places on the mana bar have been removed- they don't serve any practical purpose and they hurt my eyes. If you want to get rid of this feature, disable the client mixin "HUDOverlayRendererMixin." I tried adding a toggle in the client config, but mixins seem even fussier about client-side configs than server-side ones.

Disabled by default, there is a config option you can turn on to make it so that mana will regenerate at a static rate equal to half of the maximum speed (one minute to regenerate your full bar, if you haven't touched mna-general) instead of being dependant on hunger and saturation. Brimstone is not affected, it already always regenerates at max speed in base MnA. Enabling this setting essentially turns brimstone's regen advantage into a simple x2 multiplier.
- If you have MNAOverpowered installed, its config option for fixed mana regen will overrule my own, but turning my setting on will still cut the regen in half either way. This interaction isn't intentional, but it's good enough for me as it doesn't interfere with the default settings of either mod.

Ars Nouveau

Mana and Artifice:

Max mana and mana regen changes are applied to MnA's mana bar. This includes the boosts from your learned glyphs and spell book tier.
Casting spells uses your MnA mana instead of your Ars Nouveau mana.
Being able to cast spells is entirely dependant on your MnA mana.
Casting spells contributes XP towards your MnA magic level. The XP granted is the spell's cost divided by two (in MnA, the XP granted is the spell's complexity).
Mana discounts do not reduce the amount of experience you get.
You cannot cast spells or use spell books in any way if you have not opened up the Codex Arcana. Attempting to do so will yield the "You aren't sure how to use this item at this time" message.
The AN mana bar will never show up on your HUD.
Casting spells will instatly sync the aftermath to the HUD.
Spells can take advantage of brimstone's cast-from-health mechanic.
Spellcasting tools will work with MnA's conditional HUD mode. Does not apply to enchanter's shields.

Mana discounts apply to Mana and Artifice spells. Channeled spells have the discount apply to each second of casting. The HUD, radial menu, spellmaker, etc. all show the discounted cost. The discount is applied AFTER affinity.
The AN spellbooks go off of your MnA mana when showing how much mana a spell costs relative to your maximum.
The Jar of Voiding properly fills up your MnA mana.
You cannot learn glyphs without first learning magic.
Changed the text that appears when attempting to learn a glyph you already know from "You already know this spell!" to "You already know this glyph!" to be more accurate.
Disabled by default, the config allows you to make Ars Nouveau glyphs gated by Mana and Artifice tiers. What MnA tier matches what Ars tier is also configurable (by default, it's 1:1).

Iron's Spells:

Mana discounts apply to Iron's Spells and Spellbooks spells. Unfortunately, I couldn't figure out a good way to get the GUI to recognize the altered costs. Cost reduction occurs after the influence of affinity. The discount only goes up to a configurable percentage of the spell's affinity-adjusted cost, default is 50%.

Balancing Tweaks:

The mana regen enchantment gives only 1 point per level rather than 2. Mana and Artifice already provides vastly superior natural regen to what Ars is designed around.
Mana regen bonuses are half as effective. See above. Plus, this is balanced out by max mana bonuses contributing to mana regen anyway. You can configure the multiplier to whatever you wish.
Glyphs only grant 10 max mana and 0.16665 mana regen instead of 15 and 0.33 respectively in order to balance out the presence of MnA's leveling system. Again, this can be configured.
The amount of max mana glyphs and spellbook upgrades give depends upon your casting resource. Mana, Summer Fire, and Winter Ice are x1.0, Brimstone is x0.5, and Souls is x7.5. You can turn this off in the server config.

Notes:

AN mana regen bonuses are static, not affected by any multipliers. There's a config option to determine whether or not Undead can benefit from them, enabled by default.

Iron's Spells and Spellbooks

Mana and Artifice:

Max mana and mana regen changes are applied to MnA's mana bar.
Casting spells uses your MnA mana instead of your Iron's Spells mana.
Being able to cast spells is entirely dependant on your MnA mana, and the discounts are fully accounted for.
Casting spells contributes XP towards your MnA magic level. The XP granted is the spell's cost divided by two.
Mana discounts do not reduce the amount of experience you get.
You cannot cast spells if you have not opened up the Codex Arcana. Attempting to do so will yield the "You aren't sure how to use this item at this time" message.
The Iron's mana bar will never show up on your HUD.
Casting spells will instatly sync the aftermath to the HUD.
Spells can take advantage of brimstone's cast-from-health mechanic.
Spellcasting tools (staves) will work with MnA's conditional HUD mode. Does not apply to traditional weapons that simply have spells imbued into them.

Spell costs are impacted by the matching affinity, in addition to Ars Nouveau discounts, and also shift your affinity just as an MnA spell would. By default, the impact is halved compared to MnA spells since Iron's Spells is not designed with it in mind. You can configure the amount of influence and toggle whether or not the spells should shift your affinity. Like with MnA spells, the Ars Nouveau discounts occur after affinity. The change to cost will not be visible in the spell wheel.
Disabled by default, the config allows you to make spells gated by Mana and Artifice tiers according to the spell's rarity, You need T1 for common, T2 for uncommon, T3 for rare, T4 for epic, and T5 for legendary.
Compatible with the schools added by GTBC's Geomancy Plus and T.O. Magic 'n Extras.

Affinity Map:

Fire: Fire, Lightning
Water: Ice, (Addon: Aqua)
Earth: Nature, (Addon: Geomancy)
Air: Holy
Arcane: Evocation
Ender: Ender, Blood
None: Eldritch (can be configured)

Notes:

Regen multipliers from Iron's stack additively with each other instead of multiplicatively like MnA regen multipliers. The collective multiplier still stacks multiplicatevly with MnA's multipliers. (To be clear, this is standard Iron's Spells behavior, I'm just noting it since it's not consistent with how MnA regen multipliers work.)

Limitations

If you have bonuses to maximum mana from this mod, you will have to refill that mana yourself when you relog or repawn, even if you had that mana filled up before logging off. There isn't anything I can do about this, at least as far as I can tell.
Don't uninstall the mod right after a crash. Make sure to enter and exit the world first so it can properly run the code for unloading your bonuses. Otherwise, the bonuses might get stuck until the next time you load the world with the mod. (I haven't seen this happen before, I just assume it can based on how the mod works.)

One Mana Bar to Rule Them All