For example, he has learned how to spread his physical form across multiple bodies. As long as he has a reference, he can create "copies" of an observed creature, although the copies are quite literally an extension of himself. Orvar's intentions are cloaked in mystery.

Do copies trigger orvar?

A Copy of a Spell is not Cast. So, putting a Spell-Copy onto the Stack targeting a Creature will not trigger Orvar.

How does Orvar the All Form work?

[KHM] Orvar, the All-Form | Blue Shapeshifter Legend with two different abilities that create copies of your permanents. Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents.