The calamities+hydaelyn needing to heal the wound is verrry reiminiscent of "The Calamity from the Skies" and the Northern Crater in FF7. Jenova fell to the planet in Meteor, causing a huge scar on the planet. The planet recruited a huge amount of energy via the lifestream to heal the damage, which Sephiroth wanted to repeat, except he would be in the epicenter to absorb all the energy and be reborn as a god. In FFXIV's case, calamities are occuring every couple hundred years and Hydaleyn eats a shard to rebalance the source's aether.