Your predictions for Heavensward storyline (2.55/FcoB spoilers)

[Alberel]

Do you have a source on this? I don't recall having her mentionned that she went to visit Midgar himself. And from what I understand, Echo is exclusively something from Hydaleyn, not from anyone else.

My source is all of the cutscenes surrounding the fight with Shiva. Iceheart makes it clear that she has spoken to Hydaelyn at some point and the Echo is also how she was able to summon Shiva without becoming tempered (this is precisely why Minfillia was terrified of the Garleans discovering what happened since it proved that Echo users could weaponize primals). She tells us that she visited Midgardsormr's bones and had a vision; that was when she became a 'heretic'. You have to remember that the Echo allows you to see the memories of others so it makes perfect sense that if Iceheart was an Echo user she likely saw Midgardsormr's memories.

The Echo also is not exclusively Hydaelyn's gift to give. Hell we don't actually know if she 'gives' it deliberately or if it's just random, the actual origin and purpose of the Echo is still entirely unexplained. The Ascians all possess the Echo though as Elidibus informed us and they gave the Echo to the Sahagin priest that summoned Leviathan. The truth of the Echo will likely be the key to the entire story...

The key thing we'll be finding out in Heavensward is what end this is working towards. Omega's activation, but we don't really know what Omega can do, only that it's supposedly more powerful than Ultima Weapon was.

Omega was supposedly used by the Allagans to defeat and imprison Bahamut. I think that gives us an idea of how powerful it probably is.