Synthesist + Polymorph Effects

[Orion_Frostfire]

I have a question regarding the Synthesist who casts a Polymorph spell such as Elemental Body:

As I read the polymorph rules, I guess that when casting the Elemental Body spell while having my active eidolon suit, my eidolon gets the updated ability scores and improved natural armor, as we are one and cannot target seperately.

The Polymorph entry says:

Polymorph wrote:

While under the effects of a polymorph spell, you lose all extraordinary and supernatural abilities that depend on your original form (such as keen senses, scent, and darkvision), as well as any natural attacks and movement types possessed by your original form. You also lose any class features that depend upon form, but those that allow you to add features (such as sorcerers that can grow claws) still function.

I don't think that the eidolon itself is a supernatural ability, so it stays active; it just loses evolutions/speed and gains the natural attacks/speed and ability scores of the elemental type.

So did I miss something? Do you think the eidolon can be targeted successfully by an elemental body spell?

[Archaeik]

Well...

EB is a personal spell, so it goes through because of Share Spells.
And you aren't targeting (only) your eidolon as a synthesist... If you were under the effects of EB and your eidolon is banished, you are still under the effects of EB. (Essentially, you become an elemental "wearing" an elemental -- although that might be hard to distinguish since both would be the same size.)

As to the rest of it, it looks like you have it right... you'll lose most(there are some Sp evos) of your eidolon's powers/attacks (and gain the elemental's).
Remember to apply the Polymorph entry adjustments before the spell bonuses if your eidolon is Large+.