Chapter 15: A Reason to Fight, Part 2 is the second and last part of chapter 15 in Valkyria Chronicles 4. The combat mission is Showdown with the Valkyria.
I'll relay what we're seeing here
"The Valkyria is slowly closing in on Squad E. If we don't deal with her here and now, she'll just follow us to the capital... But the red blizzard is complicating things. It's even deadlier than her blue snowstorms. On top of that, the remaining enemy troops are rallying around her, ready to fight. And the cracked ice has completely broken apart since our last battle. Your movements will be even more restricted, so please exercise caution."
Location: Breaking Ice Shelf
Description: Put a stop to the out-of-control Valkyria. Inside Crymaria's blizzard, unit movement is hindered and HP will slowly be drained. These negative effects can be avoided by taking cover in the gaps between the rocks.
"That covers it. You're clear for deployment. Just do what you do best, Captain Wallace."