I... think... people having "aspected aether" about their person is... fanon, not canon? I can't think of an example of it from within the game, and a quick lorefinder search for "his aether" and "her aether" showed up nothing about aspected aether of a person at all.
Correct me if I'm wrong - by my understanding, transmuting personal aether into fire, ice, etc. for the creation of harmful missiles is done outside the body, after the aether has been siphoned into a spell focus (e.g. a sceptre). Like - you have one mana pool you can use to cast any sort of spell you've learned. You don't have six different mana pools (one for each elemental aspect) (or would it be twelve, to account for astral and umbral manifestations?), plus one of healing aether and one of, like, the unaspected damaging aether arcanists use, and and...
It's just one pool of personal aether. It's channeled to cast spells. In the cases of offensive utilisation of conjury and thaumaturgy, it's usually transmuted into aspected magic before being thrown. In the case of arcanima, it's just funnelled into a very precise geometry (presumably so it retains the form of "harmful missile" while reaching its target, because non-crystalline aether naturally seems to be quite floaty and vague).
HOWEVER
All that means is that, if you're keeping the thing about different personal aspects, then you're looking at fanon stuff to figure out whether your character would be able to utilise arcanima or not. I have seen it around in roleplay quite a bit. So ask around people you see using similar concepts for their characters, or the people you're going to be roleplaying with, to see what they think - since that's the most important factor in determining your character's reasonable level of aptitude!
Correct me if I'm wrong - by my understanding, transmuting personal aether into fire, ice, etc. for the creation of harmful missiles is done outside the body, after the aether has been siphoned into a spell focus (e.g. a sceptre). Like - you have one mana pool you can use to cast any sort of spell you've learned. You don't have six different mana pools (one for each elemental aspect) (or would it be twelve, to account for astral and umbral manifestations?), plus one of healing aether and one of, like, the unaspected damaging aether arcanists use, and and...
It's just one pool of personal aether. It's channeled to cast spells. In the cases of offensive utilisation of conjury and thaumaturgy, it's usually transmuted into aspected magic before being thrown. In the case of arcanima, it's just funnelled into a very precise geometry (presumably so it retains the form of "harmful missile" while reaching its target, because non-crystalline aether naturally seems to be quite floaty and vague).
HOWEVER
All that means is that, if you're keeping the thing about different personal aspects, then you're looking at fanon stuff to figure out whether your character would be able to utilise arcanima or not. I have seen it around in roleplay quite a bit. So ask around people you see using similar concepts for their characters, or the people you're going to be roleplaying with, to see what they think - since that's the most important factor in determining your character's reasonable level of aptitude!