On my first skyrim character, I was very excited about the illusion skill tree. But after reaching level 100 by using muffle repeatedly and finishing the illusion ritual spell quest, I was disappointed by the master level spells. They did not enable me to do anything new, and seemed pointless. So, I began to think about better ideas for master level illusion spells, and the best I could think of would be some sort of complete mind control. The main idea would be that your character would enter an ethereal state so as to avoid being harmed. In this state, they would be free to possess another character of your choice, who you would then gain control of for a set amount of time to do with as you saw fit. Imagine the possibilities! You could force the character to fight for you, have them commit suicide, frame them for murder, use them to infiltrate high security areas, simply put them into position for an easier kill, etc. etc. This skill would be great along with some new dark brotherhood quests that would utilize it's full potential.

That sounds awesome, I had a similar idea for Oblivion where you could take control of an NPC at any time and then your character would appear as just another NPC, but unfortunately I can't mod my way out of a paper bag . Still, this would be amazing if included in DLC or a patch.

How did I predict that the spell was gonna be "Possessing" people before I clicked the link to this thread?
Anyway, the spell doesn't really sound like it would go under the category of Illusion, the spell is creating no Illusion, you actually are taking over the persons mind o.o
the point of Frenzy, Calm, ETC stuff is that you're creating Illusions in the persons mind to get the reaction your looking for.
For example, I guess if Frenzy was casted on me I would see that everyone around me is an enemy.

Not really sure what spell school it'd go under, perhaps Mysticism if it still existed ._.

Bethesda would call it overpowered

Master fear spell, you could appear as a giant monster and all who came near would run away in fear?

I think you're looking for the 'control human' and 'control animal' spells from previous games, I wish they were back too, possibly with a master spell for indefinite control. Would be rather op when coupled with 2 dead thralls though.

The 'mayhem' spell is fantastic, pity you have to be a vampire to use it at high levels. But if you are a vampire, with a perked illusion tree and the necromage perk you can affect absolutely everything with mayhem, do remember that it has a huge area of effect.

In naruto ... hear me out.

the genjutsu is all illusion based ninja art (spells - sort of) an alot of them cause the enemies mind to fool them into thinking something else. It would be cool to see the battleground become different like a wasteland or a foggy forest (all of a sudden) and the enemies are running in panic while the Pc slips in an out slitting throats and taking names