Major Spoilers for all Expansions - Some general things I didn't understand

[Eloah]

Yeah, according to everything I know the crystal absolutely just houses the ability to do that, and if you gave it to Y'shtola she'd be able to use it for the same thing*. The notion of it somehow tapping into our Echo for this is a new one on me.

*Y'shtola would not use it for the same thing, she'd summon seven people to get research done eight times as fast.

It is stated when we are given the crystal that engraved on it is the signature spell of Azem. We learn that the Echo is just the remnants of the Ancients powers, and that any specialties the echo has, like Krile's aetherial tracking or Mikoto's ability to see into the future, are just specialties of their Ancient selves; like Emet-Selch and Hythlodaeus's soul sight. The only reason the crystal works is because it is being used by us. Only a shard of Azem is able to activate the spell. This is shown as the reason why we were always able to find allies for our fights, it's what our Echo does, we were just finding them unconsciously before, now we are using the crystal as a medium instead.

It should be noted that this is a retroactive change to our echo, as I doubt the devs thought far ahead as to what our specific echo was capable of, if anything at all. They did say that the echo manifests differently in each person, so they probably had ideas, but when it came time to implement it, they just stuck with "the power of friendship".