I read the post you originally linked which led to yet to another which led to a third that talked about Shapeshifting. Unfortunately, I am still having issues understanding based on some acronyms and other terms I don't understand readily so I have a few questions on this.
I don't think we ever made an acronyms list, so I guess it's best to just ask them here, so we can clarify.
1) I've been trying to find out how much stress you need from "Taken Out." Based on my understanding of concessions needing at least a moderate consequence, my guess is the amount required is the number of stress boxes plus three (to be just barely better than a mild). Is this correct?
Well, the thing is, you are not aiming for a concession, you are aiming to take a target out and dictate the taken out result. Lucky enough, you are the target yourself, so you are in all likelyhood not blowing your consequences on resisting your own spell. That means, that you only need 1 more shift than you can take on your stress track, which is 4 at the most, less with low endurance, so you need at the most 5 shifts to take yourself (or a willing target) out.
2) I don't understand where you got two aspects at three shifts. I read the temporary powers rules and can kind of deduce that somehow this is equal to the two fate points needed to be spent for a temporary cost two power, but where does the three come from? If you could break down your work as if you're talking to a 10-year-old (no offense to you 10-year-olds out there!) I would appreciate it.
Ah, that's on page 252, where it talks about spell maneuvers. The minimum shift requirement for an aspect done by a spell is 3. Granted, that's for evocation, but it kind of follows the same rules, when it comes to evocation (or at least that seems to be a common conception).
The two tags are indeed a replacement for the two fate points you need for the temporary power.
I understand the process of trying to reach the complexity, it's DETERMINING the complexity that I'm a little hazy on.
I thought whenever you did enchantments you didn't roll but you simply had a maximum of your Lore plus foci plus specializations, and potions were similar except you could compel aspects upon use to bump them up. Based on what you said here it seems like you can make enchantments more powerful by taking consequences and spending Fate points upon creation. Did I misinterpret this?
Yes, slightly. You've got the enchanted items and potion part down, and those are seldom strong enough to grant temporary powers (unless maybe you have a master crafter). Enchanted items can generally carry all the spells you could do via evocation or thaumaturgy, but they have a limited capacity, when it comes to shifts of power. As above, the "inhuman strength potion" requires 11 shifts of power, which is not too easy to come by for enchanted items. Potions can be boosted with aspects, so that might work, but you mostly do this for actual thaumaturgic rituals. In game, if your GM is cool with it, you can create an item, that will grant you "inhuman strength", but it is not one of your enchanted items. The enchanted items are simply those, that are part of your usual toolkit. Like Harry's shield bracelet or blasting rod, for example. Those enchanted items should probably be either skill replacement or maneuver spells.
With a 6 shift enchanted item, you could place 2 aspects like "Bull's Strength" on yourself and tag them when you need the strength to boost your rolls. That's usually the best way for most conflicts.
This is a bit more than you asked for, but bear with me. Fate can do a lot, but sometimes through a lot of different approaches.
If you want to make a character that uses potions to enhance himself regularly, you might want to look into something a little different:
Instead of taking the power temporarily, you take them permanently, but not permanently accessible. That's what the "Human Form" power is for, like werewolves and such have. You just say, that your character, a crazy alchemist, found a way to enhance his body with his potions. He is not always strong or fast, but when he drinks his potion, his body changes and he can get access to those powers. On paper, it would look something like this:
Human Form [+1]
affecting:
Inhuman Speed [-2]
Inhuman Strength [-2]
Total: -3
This would allow you to have a few potions at hand that will let you access those powers. Those potions would not count into the enchanted item slots, they would just be the narrative justification for your character to access his powers. If someone were to take away his potions, he'd need to get them back or make more, in order to access the powers again.
Of course, this is expensive, refresh wise, so you'll probably have to cut down on other powers. Evocation, for example, since an alchemist is all about the potions, not the fireballs.
You could even have another character that uses those potions, while your character is supplying him with them. Or your character is the user himself, and the alchemist is an NPC, a friend of your characters. Lot's of possibilities.