Your turn to explode

I finally managed to to finish the second mission of chapter 15 after a really drawn out fight.

The first part of the battle went well, where I flanked the Valkyria behind a smoke cloud, and managed to get up to her location, but she kept dodging everything I threw at her and healing what little damage I did. So then I figured that if I took all the bases in the map it would trigger the event to let me beat her, but that did nothing other than stopping enemy forces from spawning. Then I tried killing off all the other enemies in the level, but that also had no effect. So in the end I brought up the secondary tank to fire at her too, and i found that she could only dodge one tank at a time. So I eventually defeated her by alternating tanks until her health went down to zero.

In the following cut scene she then asks that Welkin's group lead her soldiers into custody while she stays back as the prisoner of the main army force. It turns out her plan was to make sure her soldiers and Welkin's group (who showed compassion even after defeating her) was out of range when she self destructed into a huge mushroom cloud of magical energy.

Next chapter looks interesting, the squad has to stop a gigantic hovercraft battle fortress.