1. Atomos probably start to pop for the aether from dalamud like primal hungry for that.. so he start to search and taste aether.. and he maws are a warp for the Deepvoid.. like a limbo where monsters go after death..

2. what will happen in 2.0... will be told us in 2.0!! so what bahamut will do in 5 years will be the storyline in 2.0