After the long scene, you'll be transformed into a dragon. You'll fighting alongside Rinkah, Kaze, Azura, and Sakura. Like before, avoid overstretching your units without proper support or pairing. Be careful of enemies with Wyrmslayers equipped as these would deal bonus damage to you in your current form.
While in a dragon form, you cannot pair with other characters but you can still support adjacent characters, receive support from them, and use items normally. You can also deal massive amounts of damage that can guarantee one-hit kills to your opponents. Make sure to move along with your team to avoid getting surrounded.
Ryoma will be fighting alone the invaders' leader in the far south of the map. It will be hard to reach him especially when the individual units deployed in the field can really hurt your team.
Azura is a songstress with the skill "Sing" which can allow a character to move again after ending his/her turn. You need to place her beside a unit that just finished the turn then select the option to Sing to allow that unit to act again. One of her passive skills is Healing Descant which heals up allies up to two tiles away from her up to 10% of their HP at the start of their turn. Furthermore, make sure to keep Sakura away in the rear since she can't fight back.
One of the two swordsman to the left side of the field can drop an HP Tonic. After taking care of these two and the other one with the wyrmslayer, continue south. Again, move as a group, preferably before the other reaching the next group of swordsman and two mages. The mages have at least two tiles attack range so luring the swordsman first will allow you to defeat it without support.
Abuse your dragon form's high attack and Azura's sing to attack twice per turn. Draconic rage has high accuracy and you'll get the first strike so it's possible to kill an enemy first before they can retaliate.