How does the Saia mechanic work?

I started off death mage knowing what I wanted to play. Saved up all my Diety points for the Saia first pick. (since youll want to get saia asap ro build stats) The thing is, Ive been watching the stats fairly carefully and two stats that have been the same since i got saia are still the same, im only at about realm 19 so not terribly far but i’ve killed with saia a fair bit havent seen any indication for the stat growth. Can I get some insight as to how long it should be for a stat increase? Thank you

I would also like to know the answer to this.
The information regarding Saia seems a bit vague currently.