I'm curious about the reasoning and goals of the characters supporting Seiga. I assume their interests are just coinciding in this case, and each one simply wants to take down the barrier for their own reasons.
Flandre...!Who cares about the barrier!
I need her to pay her debt for tricking me or I won't be able to calm down!Hmmm.Because the time to destroy that annoying wall might have come.Now, why are you standing in my way?