Psionics: How does Mind Seed actually work?

I am developing some NPCs for my 3.5 Eberron campaign and some of these NPCs are mind seed implants from the Dreaming Dark. After looking at the description of mind seed, in the Expanded Psionic Handbook, I realize they left out a crucial piece of information: how the spell affects the target's existing abilities.

Say you are a 15th-level psion and manifest mind seed on a 1st-level elf wizard. The elf wizard fails his save and the mind seed germinates a week later. Does the elf wizard lose his wizard levels and become a 7th-level elf psion? Or does the elf wizard become a 1st-level wizard/7th-level psion?

Suppose this happens to an existing character in a game. Suppose that as the GM I have already written up the statistics of a 10th-level human fighter as an NPC for the campaign and a player character 15th-level psion manifests mind seed on the fighter to make him a close ally. Here is how I imagine it ought to be done, but I am honestly not entirely sure.

1) Adjust the fighter's mental stats to match those of the player character psion at 7th-level.
2) Add 7 levels of psion to the fighter, choosing powers known by the player character at 7th-level, making no adjustment otherwise to the fighter's existing stats.

This would mean the fighter is already a higher-level character than the player character. Not necessarily a more powerful character, but higher-level nonetheless. It gets a bit trickier if you were to manifest mind seed on an existing psionic character.

Another possibility is to take the negative level parenthetical literally. That makes things even messier. A 15th-level character with 8 negative levels involves more calculation than a 7th-level character does. I'd rather not go the negative level route.

So this is an interesting one.

Reading the power, you actually have one part wrong:
In no way does it say they get your class levels.

"the subject becomes you in mind as you were when you manifested the power, but the subject’s level is eight lower than your own. (In effect, the subject has received eight negative levels—but these are negative levels that can’t be removed.) The subject does not have any of your physical ability scores or equipment, but does have the Intelligence, Wisdom, and Charisma scores you had when you were eight levels lower. The subject also knows the powers you knew when you were eight levels lower. "

It's actually an interpretation on if they get your manifester levels, not stated explicitly...

So, the weird way you COULD read this is:

Their mental stats become yours (from 8 levels ago)
They get 8 negative levels - or their level is 8 lower than your own - which? Who knows...
Their physical stats don't change - so how are their hit points calculated?

My suggestion is you change their levels to be you, with 8 negative levels.

I think the idea is that you're using a body to implant a previous version of yourself. The same way you implant an ego into a construct or item, you use a body instead.

They retain their physical characteristics (Str, Dex, Con, Com [if you use it], and other physical traits such as hair colour, eye colour, etc), but that is all they are of their former self.
A complete mental swap (Int, Wis, Cha), augmented with a complete memory swap to me says that they are, for all purposes, you as you you were eight levels ago.

If you were a Psi17 then went Fgt3, your Mind Seed would become a Psi12 (what you were eight levels ago).

I do not believe they would retain any of their own class levels (which could be said to be tied to the mental faculties).

Double posted for some reason.

Sekhmet said:

I think the idea is that you're using a body to implant a previous version of yourself. The same way you implant an ego into a construct or item, you use a body instead.

They retain their physical characteristics (Str, Dex, Con, Com [if you use it], and other physical traits such as hair colour, eye colour, etc), but that is all they are of their former self.
A complete mental swap (Int, Wis, Cha), augmented with a complete memory swap to me says that they are, for all purposes, you as you you were eight levels ago.

If you were a Psi17 then went Fgt3, your Mind Seed would become a Psi12 (what you were eight levels ago).

I do not believe they would retain any of their own class levels (which could be said to be tied to the mental faculties).

Click to expand...

This is how I interpret it too. Whatever they were before the mind seed is lost and replaced by what you were 8 levels ago. This includes levels, skills, feats, memories, etc. So in your example, the mind seed host would not have any fighter levels.

An interesting way for a player with a favourite high level psion to be able to adventure with a lower level party. Just mind seed some peasant and (minus some psionic items) you are good to go!