I don't think all Calamities had anything to do with any other Shard rejoining the Source? As far as I'm aware, none has rejoined as of yet, and the thirteen has been definitely spoiled. The Ascians are still at it, trying to force rejoinings, and have yet to succeed for a single one of them.
The Calamities were designed to weaken Hydaelyn's will and sap her power away. It's the exact same method that is used on all the Shards as well, with the aim to force those rejoining against Hydaelyn's will.
So far, no Calamity has succeeded yet, but it's always a step further in the direction of Hydaelyn's downfall. It is said at some point in the MSQ that the last one happening on the Source (the 7th with Bahamut) was probably the last one the mother crystal could take and was fortunately dampened a lot thanks to the efforts of the Scions.
The Calamities were designed to weaken Hydaelyn's will and sap her power away. It's the exact same method that is used on all the Shards as well, with the aim to force those rejoining against Hydaelyn's will.
So far, no Calamity has succeeded yet, but it's always a step further in the direction of Hydaelyn's downfall. It is said at some point in the MSQ that the last one happening on the Source (the 7th with Bahamut) was probably the last one the mother crystal could take and was fortunately dampened a lot thanks to the efforts of the Scions.
Balmung:Â Suen Shyu
