New Player Lore Questions

[MrThinker]

So how is it that Ysayle can turn into Shiva?

I feel like they explained it in the story but I still don't really understand how. I am now at Ravana storyline.

Primal summoning can be separated into 2 broad strokes: the usual incarnate summon, and then avatar summoning, in which a living host takes on the soul of a primal, transforming them into the primal. It is this second method that Ysayle uses.