Your twisting thing as always and basing yourself on nothing.

Sephiroth chose his destiny !
Were ppl of Shinra controlled ? NO
And they were working for Shinra just like Sephiroth was working for Jenova.
They chose the path they BELEIVED IN !
He did it for Jenova and def. not cause he was controlled by Jenova !
Your asumming is just as bad as always.
What about Cloud, Hojo, Nanaki, Vincent, Lucrecia, Zack and members of SOLDIER.
Were they controlled by Jenova ? NO
Yet they all were injected whit Jenova cel !

Jenova was controlling Sephiroth ? Is PURE SPECULATION! We are never TOLD that Jenova control Sephiroth.
He does care for Jenova as a mother not as a puppet.

Edit:

As for when Sephiroth kill Areis the only thing i see his him pull up a little smile of satisfaction as he pull the blade out