The way I understand it, is that Lahabrea went around teaching a limited version of Ancient creation magic with a specific tempering thing built into it to keep the cycle going.

When it comes to summoning "faith" is not being used as emotional fuel, but instead as a clear image of the being to be summoned. All of the summoned beings are gods or at the very least ideals (as in Shiva's case). The people summoning them are Sundered and so have very limited power in creation magic compared to the Ancients and need outside help. But together with a power source (crystals) and a common, strong faith they all have together in a single shared idea of a being, they can perform creation magic. When a clear image is not formed, like with Ga Bu's summoning of Titan, the summoning goes wrong and Titan's personality was warped by Ga Bu's state when he summoned him.

So summoning, at least to me, is purely aetheric and has nothing to do with dynamis at all.