Saias = Blue Arvis correct?

He have a similar stat line to Arvis and the same tome, but i don't know about the others skills.

Yep, he's pretty much Blue Arvis.

They made him blue so he can counter Arvis and finally get that child support

He is essentially a blue Arvis tilted slightly more towards defense than offense (1 less point in Atk and Spd, 1 more in Res and Def)
He comes with
Wargod's Tome, a 14 Mt personal tome with Atk/Res Ploy 2

Escape Route

Spd Ploy

And Glacies