Cause of ascian calamity and rejoining elemental

[MrThinker]

1.what is cause of ascian civilzation calamity that nearly break world
Apart that make ascian created zodiark

Natural disaster meteor? Or fail experimental breakout

2.13 shard + 1 main world
What is 13 elemental of rejoining that not yet reveal

1.fire
2.water
3.wind
4.earth
5.lighting
6.ice
7.non-elemental bahamut
8.Light (nearly succeed in 1st shard but fail because champion and
Scion of seventh dawn and zenos)
9.Dark (fail to munch darkness in 13th shard)
10.?
11.?
12.?
13.?

What 4 elemental of yet reveal

Just a correction, it is revealed that Bahamut was a Darkness-aligned calamity. Yes, the 13th may have been a failed attempt to cause a darkness calamity, but they succeeded with Bahamut.