Siren, Dark Fina & Behemoth Boss Guide

Encounter preparation

Boss	Useful element	Main problem	First change
Siren	Lightning	Charm / Allure	Equip Charm prevention; keep recovery available.
Dark Fina	Water / Light	Paradise Lost / Dystopia	Move healing to an available member; Dark is resisted.
Behemoth	Wind / Light	Meteor / Paralysis	Protect recovery; inspect physical or magic blocking states.

Siren: prevent loss of control

In Chapter 1, Grandport’s story leads to Siren’s Tower. Prepare Lightning commands and Charm prevention. Tronn provides Thunder; Prayer Beads and Leah’s Nullify Charm are preparation options in the encounter reference. Confirm equipped effects before entering. Use weakness pressure to pursue an interruption, but retain a recovery action if Allure resolves. Victory unlocks Siren; the following Fina dialogue is a separate stat choice.

Dark Fina: keep healing when Fina is absent

Reveal Chapter 5 tactics

On the second Psyche visit, use Water or Light and give Leah or another recovery option to someone who is available. Paradise Lost boosts Dark and reduces other elemental damage; it does not make Dark a weakness. Dystopia is a dangerous party-wide Dark attack that Stagger can cancel. If you cannot break the gauge in time, use the remaining actions to stabilize instead of exhausting recovery on weak attacks. Recheck elements before the following Tellus fight, which calls for Wind.

Behemoth: read both element and stance

Reveal Chapter 8 tactics

Allow the opening story support to resolve. Once normal combat is available, use Wind or Light and keep Paralysis recovery off the same single character you rely on for healing. Try to interrupt Meteor with Stagger. After a physical-blocking warcry, switch to magic; after a magic-blocking warcry, use physical attacks. Changing attack type without checking element can still leave damage low.

Make a failed attempt useful

Write down which action caused the loss.
Change the relevant protection, element or command assignment.
Restore resources and preserve your pre-battle save.
Try again with a specific response to that action, rather than assuming more levels alone solve it.

Continue your journey

Story route · Visions · Completion planner

Sources & review

Reviewed 29 October 2026 by GameHelpBase. This guide compares published references; it does not claim an independently recorded playthrough. Patch-specific behavior is not verified.