A Blue Flower from the Pray War warps to Tobal in Ep0 - Ch67. It attacks and destroys almost every continent except Lian. Leny together with the Cold Heroes Sion and the Original Chimera destroyed the Blue Flower from within, thus securing the retreat route for the fleet led by Dry in the Battle of Arin.
However the Blue Flower was excessively damaged by the Chimera going berserk. Since it was still inside the planet's atmosphere significant debris fell to Tobal which caused erosion of the land. This angers General Nelson who decides it's time to end Knight Order's influence on Tobal. With refugees rushing in from allied regions and enemy states as well, the President Billy in Lian , a loyal servant of the KO, is worried about his position and closes down borders.
After this event Sion was asked to take the blame for the Blue Flower incident as they did not want to reveal the Chimera project to the outside. Since Sion wants to protect everyone she agreed to this even though she'd be abandoned by the Knights and hated by the very people she saved.
"Jan 3rd, 431 Cosmic Century. The 10 day war was over." (AE2 - Ch2)