Why did it take so long for the Solar Alliance to declare war on PACT? The political reason is the gridlock in Congress and its lame duck president. Then the Prototypes appear, one ranting how they have control over the galaxy's leadership, their mask as PACT's Supreme Leader is just one of them. In other words, the Prototypes organized the whole war without anyone realizing it.
During the Battle of Far Port, despite having the Legion that could turn the fight around, Arcadius still declares a retreat. The PACT fleets are too disorganized thanks to Cullen's poor strategy. The Solar Alliance just arrived with new ships, lead by a much more competent commander, meaning a war of attrition. What further puts them against their favor is the sudden awakening of Asaga's Sharr powers, which the Prototypes are aware of. In others words, a complete wild card in the enemy's hand that could turn the tide against you even with the Legion. With these three factors put together, the battle is heavily against PACT and retreating is the best option.
In the sprites in Sunrider Academy, Chigara has two sprites that have sparks going between the loops of the bow on her head. While it may be seen as simply a cute reference to her being frazzled or surprised since she loves science, it actually makes sense in that her Mask of Arcadius counterpart have built-in stun guns within her hairclips/bow so it's quite possible for her hairclip/bow to actually spark!
Following Sunrider 4 is the existence of space whales. Ongessite is known for being a material crucial for warp drive systems, which were made by krill found on the planet many years ago. In other words, space whales exist simply through Organic Technology, using their blubber as biological warp drives.
One for Sunrider Academy - specifically, the Sola route: If you play any other route, this version of Sola will be erased from existence, along with your and everyone's memories of her!
Not necessarily. A brief conversation in another route implies that she got Chigara's help in a 'certain matter' she does not elaborate on. So it's implied that, even if you don't choose her route, she is likely still to get off-screen help in the form of Chigara.
Also worth noting that there seems to be a degree of alternate universe about each route unrelated to Kayto's actions, with each girl's personal problems seeming to be less dramatic if you don't pick their route. For example Ava's heavy handed management of the Student Council never quite hits the crisis point that it does in her own route if you're with another girl and I can't see how Kayto being in love with her would have had an effect of that. If you're not on her route Sola's issue is presumably just easier to fix.
The Prototypes have control over the galaxy's leadership, including the Solar Alliance. Fontana's expose of the Prototypes has also gone public. This is frightening and heavily damaging to the Solar Alliance for several reasons.
Imagine being the common citizen in the Solar Alliance, then learning your government is under control of genetically engineered superhumans who also rule the enemy you're fighting. Being someone who values freedom and has lived in complacency for the past 100 years, how panicked and disillusioned would you be of your very own government?
Next would be the President. Now that the master has been exposed and you as one of its puppets, think of how dramatically low your approval rating is now.
Finally, a member of the Progress Party, which has been trying to look for a peaceful resolution with PACT and prevent militarization. With your popularity plummeting for being a suspect of the Prototypes' manipulations, those fears just now might've came true...
