I've decided on the general characteristics: the brainburner is a mostly sessile monster that a) cloaks itself in an attractive illusion, b) lures its victims closer even if they see through the illusion, c) drains their minds when they are near. Unfortunately, I'm having problems with all three of these aspects. I invite and request commentary on each of these.
The Attractive Illusion
The most attractive illusion might be a pool of water, and that would fit the fact that this is fundamentally a mirage. On the other hand, my players are canny, and will regard this with the suspicion of J. Edgar Hoover regarding... well, anything. And rightfully so. They might have the PCs fall for it if the rules said so, because they're obliging players, but they would be suspicious. But I think it would be better if I had an attractive illusion that actually was attractive to the players.
The Compulsion to Approach
My difficulties with this one are mostly a question of mechanics. I could certainly say "Will save, DC X, or approach the brainburner," but I enjoy using mechanics that resemble the mechanics of other parts of the system, so I'm trying to use other mechanics to model this.
I considered a gaze attack with the effects of a command spell. I like the effect of the "approach" command, since it includes both "approach" and "do nothing else". But that has several discrepancies with what I have in mind:
- Gaze attacks have a range of 30 feet by default. In fact, all of the gaze attacks in the monster manual have a range of 30 feet. I have in mind a longer range.
- It's not clear to me that a gaze attack would work when the monster is concealed by an illusion.
- The command spell is marked as language-dependent.
This might still be a good approach, but it's got enough discrepancies that I find myself looking for another approach.
Another approach might be the "fascinated" state caused by the hypnotic pattern spell and similar spells. My quibbles there are these:
- most fascination effects don't make the subject move closer
- fascination is pretty easy to shake someone out of, so I want an effect that people risk succumbing to again and again. (This is why I considered a gaze attack earlier.)
The spell rainbow pattern does let you lead subjects around. I could consider giving that as a spell-like ability. But with the hit dice limit as written for rainbow pattern, it couldn't include all the PCs. And I have the same problem of wanting repeated risk of submission that I wanted with the previous choice.
Ability damage to one of the mental stats is an obvious choice, but I'm waffling about which mental stat it should be. I'm reminded of the mindfire disease, which drains Int. But at the moment, there is no PC in the party who is very attached to Int. Damaging Wis could be worse--particularly if Liandra takes enough Wis damage that she can't cast restoration or a variant thereof. On the other hand, she has very good Will saves, so she's probably not at too much risk. Draining Cha would hinder Larissa more, and be more recoverable.
On the whole, though, I'm leaning more towards Wis--it seems more like what would be damaged by the sense of your brain being on fire.
Comments? Feedback? Suggestions?