You'll have to divide your army into two groups once again, your most powerful characters leading the charge. Keep your healers at a safe distance and pair up your individual units to give them the much needed boost and protection against the mighty dragon. However, don't even think that you'll reach his claws that easy. As soon as the battle starts, Anankos will summon a handful of units surrounding your army.
Head and destroy them but don't go far scattering your forces to take them out. Head towards the claws and deal with the nearest ones first. Anankos will keep summoning two more reinforcements so you should have extra units that can engage and destroy them within the turn to avoid getting overrun. The placements of these reinforcements will be different every turn.
After taking out the hands, Ananko's head will be lowered and you'll be able to target it. Like before, regroup your army in front of its head, just outside its attack range then heal up and gang up on it. Once it has been weakened, deliver the finishing blow to destroy its body.
Finally, the core itself will be revealed. If you destroyed the body within your turn and you still have several units yet to take action, use them to heal your main attackers. If you have Azura as a songstress and still available for action, you can sing to your main attacker then have one of your healers “Rescue” one of the units who finished their turn so another ranged unit can attack and weaken Anankos enough for your main attacker to land the finishing blow. If this is not possible, you'll have to keep in mind the summoned reinforcements and stay away from their attack range so you can finish off Anankos in the following turn.
Congratulations for finishing the third and final route of the game!