At what point does the RNG determine things like shiny/IV after being interacted with?

Question

So if I were to talk to a static legendary, would the stats be determined as soon as I talk to it or sometime in the battle intro?

Comments

Not meaning to sound rude, but does it matter?

Answer 1

When you encounter any Pokemon, (Including static Legendaries.) its stats will be determined immediately when the battle starts.
Hope this helps
Source: Experience