In the last chapter, you will travel to an ice-bound location. You have to watch out for streams of water here and you will encounter many fire and ice opponents. Remember that lightning attacks are the most effective against the former, and fire attacks against the latter. To continue the story, you have to move right, but there are many collectibles in this location, which may prove helpful against the final boss.
If you decide to explore the right side, you will find an Elemental. He will ask you to collect 10 glowing items scattered all around Lemuria. You can find them next to shrines like the one in the above screenshot. You only have to fly up to them and press the action button.
Another mission that you can complete here is the one that you have received from the statue in the previous chapter. You have to light up the stones with Igniculus.
In the first part of this location, you have to watch out for the shards of ice that electricity flows through. It wounds Aurora.
Sea boss and a puzzle
If you keep moving left, you will cross the ice-bound part of the map and the coral one. After you pass by the statue, by which Aurora learns about the condition of her father, you will be attacked by the boss. He is a water opponent, so he is most vulnerable to electricity. After you kill him, move the lever on the left - it has been shown in the above screenshot as circled in violet. This will open the door to the next part of the location. Cross the door to find a puzzle.
Using Igniculus, you have to direct light onto correct symbols. Pairs to make have been circled in color, in the above screenshot. You have to do that in the correct order. First, do the yellow one, then green, red and black. This will open the door to the next location.
2 final bosses
Once you make it into the next location, you will have to pass by all of the traps above them. Then, fly down and pull the first lever. This will open the door into a room, where you meet Nox. She will run and the entire room will fill with poison. You will have some time spare to turn two cranks, which will allow you to escape the trap. While flying, keep healing Aurora, or she will die. After you open the passage, fly to the very top. Be quick, because the mechanisms behind you will keep dealing damage to you. As soon as you reach the top, you will have to fight Nox. She is a water monster, vulnerable to electricity.
It is a good idea to heal your companions towards the end of the battle with Nox, or right before it. The final boss is a dark monster, so attack him with fire and light attacks. After the battle, the game draws to an end, but you can keep playing.