This battle takes place atop Mt. Kilamanjaro. Freezing cold and deadly enemies; what a combo. This mission could in fact be one of the easiest missions ever.
The first battle is against none other than Four Murasame in her Psycho Gundam. She's much, much easier now than she was in Mission 11.
This is the Psycho Gundam's strongest attack it isn't really THAT strong. At level 25 you'll only take 001-002AP damage for every shot Psycho lands on you, but you'll still only be dishing out 002-004AP damage to the Psycho. Once you've inflicted 10AP damage (that's right, TEN) the Psycho Gundam will fly off.
This is a pretty cool scene because it shows how to enemies can set aside their own differences and fight together for a greater cause. You have to fight the Psycho Gundam two more times; the above information applies to the next two encounters.
It can't be! It's Jerrid! He's suppossed to be dead! Jerrid's back and ready to kill you with his new mobile suit, Byarlant. The Byarlant is faster but not stronger than the Zeta Gundam. Once you land a hit on the Byarlant it flees the battle.
You'll head into a Close Range battle with the Byarlant. The Byarlant can inflict 80-100AP damage with each hit but you should be able to return twice as much damage to it. After the Byarlant is dealt 1000AP damage or so Four flies in in the Psycho Gundam and saves Kamiyuh from Jerrid's final blow. Jerrid manages to flee but Four isn't so lucky...