Devolution

[Bao Hadir]

If I'm a level 15 Summoner and I want to cast Devolution on my own eidolon (say just to remove its huge size so it can fit through a doorway) can I

A) Cast it at a low enough level to only remove 1 evolution?
B) Create a scroll with a Devolution that I have used Extend Spell on?
C) Have my eidolon not attempt the spell's Will save?
D) Choose the specific 4-point evolution to remove?

[Ridiculon]

I could be totally wrong but I'm pretty sure that giving up your will save is always an option, and since you control your eidolon(right? or do they have their own personalities?) you get to choose for him

[Diego Rossi]

A) yes, you can lower your casting level when you cast a spell, down to the minimum casting level needed to cast the spell, but the lowered casting level affect all aspects of the spell.
B) Yes.
c) If he want he can waive his save. The eidolon is a separate creature from the summoner so it is his choice. As they share goals and alignment generally he will agree.
D)No. Devolution say: "Evolutions with the highest total cost are lost first. If there is a tie, randomly determine which is lost.