Ni no Kuni: Wrath of the White Witch

Story related, cannot be missed. Earned once you defeat the last boss and view the credits.

The final boss has 3 forms, and the 3rd form is quite hard. He comes with 5 pod enemies, and he constantly casts 4 spells in order - Chaos (HUGE AoE damage, interrupts your actions), Piercing Gaze (lowers stats of target, interrupts your actions), Sigh of Sorrow (breath attack in front of him that causes sleep status), and Shock Blast (AoE damage around him, can be avoided by running away). If Chaos kills someone and he still has Eyes alive, the battle can get messy really quickly. Spam your own AoEs, and focus on taking out the Eyes as quickly as you can. They do enough damage that they can seriously hamper recovery from Chaos. After you kill them all, they stay dead for a little while, then start slowly respawning 1 at a time, so take them out as fast as you can.

The NPC that fights with you will occasionally stop Chaos (and put the boss in CHANCE mode for bonus damage) and also has a revive spell to help you recover, but don't rely on her since she can't do anything when she gets swarmed by the Eyes. Luckily, she's invincible...