Griever

[Serapy]

The point is that Rinoa is involved, which makes it complicated.

How is Rinoa involved? Besides the fact that she she sees a cool ring on someone she has a crush on, and then asks for a copy to be made.

Compare her general reactions to her specific reactions when it comes to the Griever thing.

Really, this is getting far too much. There is no way to determine whether Ultimecia found the GF Griever, or whether she pulled it out of Squall's mind. I believe the former is more likely, seeing that Squall does not necessarily fight Ultimecia at the end, which complicates matters, but there is no proof one way or another. But to try manipulate Griever's role in the game to prove R=U is ridiculous.

Yes, there's a way to determine.

For example:

Matron gained powers off Ultimecia.

Matron begun to know about Ellone after she came to the orphanage (She learnt about Ellone).
Which explains why Ellone left the orphanage earlier because she was scared of Matron due to her powers that were recieved by Ultimecia. Proof: you see little Squall calling Sis... at the orphanage for many times, which indicated that Ellone left him/the orphanage in the first place.

Later in the story, Ultimecia possessed Edea.

While possessing Edea, Ultimecia has just found out about Ellone and her special power.

Ultimecia begun looking for Ellone.

So, based on that logic:

Rinoa learnt about Griever.

Ultimecia possessed Rinoa. While possessing Rinoa, Ultimecia has just found out about Griever.

In the end, she summoned Griever.

The point is that if Rinoa has never learnt about Griever in the first place, there is no way that Ultimecia could summon Griever. Ultimecia can't just gain knowledge, unless she possesses someone.