Give that Molly raidiates like a nuclear bomb to anybody with magical senses, and neither stop her being magically detected, against anybody that matters both are useless for Molly.
This has been litigated before, and ruled on by the QM.
BMI hides Molly's doom aura.
DP has previously confirmed that BMI can perfectly conceal our supernatural nature, including the Aura of Nuclear Doom, against any sensory powers short of direct observation from a Wizard's Sight.
^^^
I don't see us needing to disguise ourselves often enough to make Black Mirror worth it. I also expect that if anyone finds out we can hide our aura of infernal majesty we might have a bit of a diplomatic crisis with extremely concerned wizards.
To be fair they might shrug it off, and it's not like we need to care a ton about their opinions, but I also kind of like the aura and how it constrains our behavior.
Everytime we used Rendered Villain Dispersal to teleport by water, we roll for alerting everybody in the vicinity that Molly just travelled from Chicago.
This was explicitly a plot point when we went to assassinate Arianna, and the Fellowship of St Giles tracked us down to the airport and we almost had a gunfight there with the people who thought they were defending mortals from a bigass monster.
If the Reds had been more on the ball, that would have warned Arianna off.
Can someone explain what are the actual plans for BMI use? Because from my perspective, BMI, as great a charm as it is in vacuum, is either redundant or actively self-defeating in Molly's current situation.
As I understand it, there are two main scenarios:
1) Conceal Molly's infernal status, and DPE. We have ATP. BMI is longer, yes, and allows for easier social interaction, but it's essentially the same functionality
2) Disguise as someone else / use it for stealth. The core flaw of BMI is that it can be reasoned through, and doesn't edit memories. People can deduce that it was Molly in disguise. Which makes it detrimental to use, because after one, two, or three uses, our enemies will figure out that we have a perfect disguise charm. And while I don't believe that Anduriel is watching us sleep right now, they will be forced to observe Molly 24/7 once they learn of this charm's existence.
Basically, BMI is a great charm, but we can't use it often or almost any time, except in emergencies or situations where we can be certain that there will be no witnesses or records.
Everytime we use RVD, we will have it active, so we can pass through the area without alerting every spirit within five hundred miles that something Big just passed through the local waters.
Again, see Mexico for how that almost turned out.
And it means we can avoid leaving magic traces for people to check, like they did in Vegas when we showed up.
Then when we are talking to minor talents, we can do so without a malus.
See Pauline Moskowitz; if you notice our first contact with her, we had to roll more than 10 successes to get her to sit down, or she would have fled, despite Michael literally being beside us.
Then when we get Splintered Gale clones, it makes it that much harder for enemies to differentiate.
That both obfuscates what Molly is doing at any given time, and it makes the clones much safer, since our enemies wont know which is full fat Molly Prime with all the smoke.
AND it makes it harder for them to plan around cities where Molly has a known presence.
And for just one mundane application:
Molly can change her hair color, texture and appearance at will.
And that was something that Molly allegedly learned alchemy for in canon iirc, so its important to her.