My estimation of Sola's ending is Not End yet.it's possible Aono may defeat Matsuri in first round and cease temporary control of
Yorito.But Matsuri will not accept the defeat and prepare to retaliate.so There must be season2. I believe the remaining 3 eps won't be enough to explain everything So in s2 the background of what's Yaka and hero/heroine's past will be complete unfold.
My Scenario is:
s2 happen in year around 2030-2050 due to heavy Tiberium infestation on earth Aono may switch paper to Tiberium as her medium to manifest her power(she may also join the Bortherhood of NOD).This would be her undoing, soooner or later
Matsuri will figure out Tiberium's vulnerable to certain sound frequency.With GDI Sonic Disruptor technology Aono will be easily squashed.In ep6 of s2 Matsuri launched a final assault on Aono's stronghold.During the fianl battle she's having difficulty in breaching Aono's castle so the Ion canon is activated.Unfortunately it;s Aono's setup the Ion Canon strike detonate the huge amount of liquid Tiberium under her castle.The blast
signaled the Scrin(their forman is Yoko Amamiya) to invade and mark the begining of another 6 ep