Which is basically what I was suggesting.
Except start Mystic Arcanum at level 1.
Level 1
Cantrips -> At-will -> Cantrips.
Pact Magic -> Encounter -> Sword Art (scales)
Mystic Arcanum -> Daily -> Arcane Casting.
Level 2
Invocation -> Utility.
Level 3
Aegis as a subclass.
Aegis as part of the subclass thematic is great.
Because 4e powers can translate variously into 5e − class features, spells, feats, etcetera − it helps to focus on concepts and on whatever mechanics are known to work well in 5e.
My impulse is that the 5e Swordmage need not be too slavish in modeling the 4e mechanics. Albeit if that proves to be useful in 5e that is fine.
In the example above, I am unsure why the Level 1 Swordmage needs both per-rest slots for "encounter" and per-long for "daily" when both are choosing from the same spell list. (Unless by "Sword Art" you dont mean spells?)
The 5e "Invocation" can be anything, whether a social or exploration "Utility", or a combat effect. I prefer this. 4e didnt really work anyway, since the "good" Utilities were the ones that were dual use being effective in combat, like mobility, stealth, and AC boosts. Let the Invocation be any kind of class feature.
Unarmed was a weapon in 4e. So Swordmage could use it. It just wasn't very good, even with feats.
I guess, but some 4e Swordmage features required the use of a "heavy blade" or a "light blade". That bothered me during 4e. I hope the 5e version makes clear the Swordmage oneself is the "blade" figuratively, personally, in the same way that the Aegis has the Swordmage oneself be the "shield" figuratively, personally.
5e's Tavern Brawler is a bit better, and can be used with Booming Blade.
5e has some weird allergy to using the body as a "weapon". This weirdness seems nonuseful. It was better designwise when the Unarmed Strike was listed on the Weapon Table, as an innately proficient weapon. Fangs, claws, and horns might offer Slash or Pierce, instead of Bludgeon, and some classes could improve or augment its damage.
Incidently, the 5e format should probably refer to the "Weapon" damage type and give up on distinguishing between Slash, Pierce, and Bludgeion. The edition never did anything significant with the extra complication.
"Magic" and "spells" are not directly linked.
A wild magic sorcerer turning into a potted plant is very much magic, but not a spell.
If I remember correctly, in the context of the psionic power source, the 5e designers commented:
• magic can be a spell
• magic can be not a spell (such as a class feature)
• magic can produce an effect that is itself nonmagic
In the context of psionic, I view the mind itself (being the consciousness level of the "soul" and that associates with the Astral) is nonmagical. But because of the nature of magic itself being "psychosensitive" the mind can exert magic by means of intention.
And "spells" tend not to stack, with concentration. You don't want to be able to have scaling force armor and mage armor and turning into air all at the same time.
But is true for all spell casters. The concentration effect that makes stacking impossible is part of the reason for better balance between casters and martials. (However, martial classes need to have a way to exert narrative control at the highest tiers.)
There are a few, like mage armor and foresight. But seems far simpler to just do it directly.
I.e
Armor of Shadows -> Mage Armor -> 13+Dex AC
Vs
Armor of Shadows -> 13+ Dex AC.
The first is both more convoluted and leads to an Abjuration exploit.
Exactly. Probably
Mage Armor itself can have a class feature to augment it, to make it at-will, and perhaps add Intelligence and-or Proficiency to its AC.
Note, the
Mage Armor spell is already almost an "always on" use of a spell slot. Its 2014 duration lasts 8 hours. Casting it twice makes it active while awake, and casting it three times with diminishing returns makes it active at will, always on 24 hours a day. The spell description itself should probably just be a 24 hour spell duration. As-is currently, it is almost the same thing as Medium Armor Training. The spell description could be made the same thing as the Unarmored Defense that the Monk (+ Wisdom) and Barbarian (+ Constitution) have, but the spell adds "+ your casting ability" which for the Swordmage would be + Intelligence. Thus the spell grants 24 hours of: AC 10 + Dexterity + Casting Ability (Intelligence).