- "Aqua Pentagram... An absolute defense made out of water. Now, you won't be able to lay a single finger on me. This isn't an ordinary barrier. There are only five users of this technique in the world. It manipulates time and space to completely nullify any physical attack. No matter how strong, they cannot break through. Haha... Have you realized that you have no way of winning?" - Kraken
The Aqua Pentagram, also known as Aqua Pentagon, is a special water-based technique used by Kraken, Undine, Erubetie, and two others. This skill forms an aquatic barrier that apparently manipulates the fabric of time and space to reflect all physical attacks and render them worthless.
When Luka starts overwhelming Kraken in their battle, she casts this barrier, making Luka's attacks useless. Alice appears in a corner and uses "Eye of Hypnosis" to make Luka sleep, thus activating his angel powers. Luka easily slashes the barrier with Flash Kill, leaving Kraken shocked.
When Erubetie attempts to murder Luka with "Melt Storm", Undine intervenes and safeguards Luka with Aqua Pentagram, then informs her friend that Luka came to meet with her. Erubetie, deciding to let Undine handle the human, retreats.
In the final battle with Goddess Ilias, Erubetie appears to protect Luka and Alice with Aqua Pentagram. However, Ilias instantly destroys the barrier with ease, using her skill "Holy Flare". Nevertheless, Erubetie begins shielding her comrades with her own body until she reaches her limit.
- It is possible that Poseidoness, the ruler of the Northern Seas and a friend of Kraken, is also a user of Aqua Pentagram.
- Alice, the sixteenth and current Monster Lord, might be a user as well. However, this is questionable, as she stated once in San Ilia Library that she's not good in water magic.
- This is the only skill that the player does not have direct access to.
- Despite being called "Aqua Pentagram", the skill is depicted as a hexagram-shaped barrier.