Question

What archetype poses as an ally?
the trickster, shadow, mentor, or shapeshifter?

Answer 1

I'm gonna assume it's shapeshifter, since they can transform into different beings (hence, they could pose as an ally)

Answer 2

It could be all of them, trickster would trick you, "shadow you would expect to always have your back, mentor while he teaches you he could be plotting to kill you.this is what i think.