We're far more likely to run into a god, ghost, or demon that needs killing than we are to run into a geass user. And a lot of Geass's wouldn't be Shaping, like the mind reading Geass, or the combat precog Geass.
Assumption of Mu will deal with mind reading, as it should give info on what we aren't thinking. Combat precog geass I think likely works on reading Fate which we don't have, and even if it doesn't Assumption of Mu would make it give incorrect info.
The effects of Geass likely fall into three categories...
1. Shaping - These are the worst. Things like Absolute Command likely fall under this. These are powerful, though seem to have limitations like needing eye contact.
2. Unnatural Mental Influence - Bad, but we can spend WP to stop it.
3. Passive/Permanent - Mind reading, combat precog, etc. Might be a "Sorcerous" class.
But as I said, Shaping in general is something we'll want a defense against. Exalts can use them.
Also, we already have a spirit-killing Charm. Reality Raking Claws - it even turns them into a Crafting Material as a side benefit. Hell, we don't even have to use it for the finishing blow, or be the one to strike it. Just using it and successfully hitting means anyone else can kill the spirit in question.
A few questions about your Plan:
Didn't you want to add an offensive Malfeas charm (Green Sun Burst?) but lacked XP the first time? Why not now? And where is that awesome one that deals damage if the target tries to Dodge or parry? I few we really need a personal offense option. Demon Puddle proved that the Hellcaster doesn't cut it, thus why I'm recently asking about Sorcery. We should also get a new rifle or two, for missions like these.
Wouldn't this be a good time to learn MA? Or Sorcery?
Isn't Nemesis Self Imagined Anew up there on our priority list, to allow us to quickly raise Essence levels? Btw, is there any special requisite to raise Essence to 5 (and above) and atributes to 6 (and above)?
1. Green Sun Nimbus Flare was a priority, and it's still up there on the things I want, but there are other priorities at the moment.
2. Martial Arts would be nice, but we don't have time I think, and we don't have anyone to teach us the MA Charms for Hellfire Ballet Style quite yet.
3. Sorcery is a nice to have, given that Rakshata currently has it. She can summon any demons we need and tell them to obey our commands.
4. I'm not quite sure what @Alexander89 means by Nemesis Self Imagined Anew giving a way to increase Essence. He'll need to explain that. I could change it with sufficient reason to do so.
In my opinion, the problem with plan Enjou is that it wants us to generalize far too much, and in a suboptimal way. We're primarily a social character, so if we get combat stuff, we should be getting it cheaply from our favored Yozis, not expensively from Malfeas.
I know we're primarily a social character, but within our Coven we're pretty much the only one likely to become the second combat oriented character - this has been discussed in depth before. And in the last couple days we've been in two battles, and nearly a third against a giant fucking poodle!
Being the secondary combat character in our group of five is one of the big reasons we got Malfeas Charms in the first place rather than something else. They make combat much easier by making your character able to take a beating and keep on moving. I also want Countless Cities Clotting because Lelouch is living a double life, and so being able to heal up overnight is kind of important to maintaining that - we can't just say things like "I fell down some stairs" repeatedly and have it be believable. (plus Lelouch would lose too much SAN from his fan club trying to nurse him back to health)