Boost Level

Boost Level is a system where skills will become more powerful or gain more effects as a battle continues.

Mechanics

At the start of a battle, Boost Level begins at level 0. A skill's current Boost Level can be checked by looking at the skill's description during battle.

At a given Boost Level, the demon's skill receives the benefits for that level and all previous levels. For example: at Boost Level 3, the demon receives the benefits of levels 1, 2, and 3 simultaneously.

Boost Level is retained across waves and if the demon dies. There is no way to decrease Boost Level once it has been increased.

Boost Level is tracked separately for each skill on each demon (though demons tend to have only one boost-able skill), and generally a demon can only increase the Boost Levels of their own skills (with some exceptions, such as Gemori).

Boost Level increasers

Demon Panels that increase Boost Level at the start of the 1st turn

Demon	Panel #	Effect
Cerberus A	Panel 1	+30% to Phys hit rate. +20% to Max HP. Activates the following Chain Effect at the start of the 1st turn: Adds one Boost level to the one with this skill's Hell Blaze, and then decreases the DEF of all enemies by 20% (1 turn).
Gemori	Panel 2	Activates the following Chain Effect at the beginning of the 1st turn: Increases the Boost level of Skills with the [This skill will gain 1 Boost level with each use] effect of all living party members by 1.
Guts	Panel 2	+20% to hit rate. Activates the following Chain Effect at the start of the first turn: Adds 1 Boost Level to the one with this skill's Dragon Slayer skill.
Quetzalcoatl A	Panel 2	+20% to Max HP. Activates the following Chain Effect at the start of the 1st turn: Adds 1 Boost Level to the one with this skill's Aztec Pulse skill.
Sukuna-Hikona A	Panel 2	Adds Null Mute/Charm. Activates the following Chain Effect at the start of the 1st turn: Adds 1 Boost Level to the skill holder's Descent of Ice and Snow skill.
Surt A	Panel 3	+25% to Fire damage. Activates the following Chain Effect at the start of the 1st turn: Adds 1 Boost level to the one with this skill's Eruption, and then decreases the DEF of all enemies by 20%. (1 turn)
Vishnu A	Panel 3	+20% to max HP. +20% to Light/Dark damage. Activates the following Chain Effect at the start of the 1st turn: Adds 1 Boost level to the one with this skill's Nirvana skill.

Demon Panels that increase Boost Level when attacking first

Demon	Panel #	Effect
Cu Chulainn A	Panel 3	+20% to Phys/Force damage. Activates the following Chain Effect when attacking first at the start of a battle: Adds 1 Boost level to the one with this skill's Barbed Spear, and then decreases the DEF of all enemies by 20%. (3 turns)
Garuda A	Panel 3	+25% to Force damage. Activates the following Chain Effect when attacking first at the start of a battle: Adds 1 Boost level to the one with this skill's Gale Talon, and then increases the ATK of all party members by 20%. (3 turns)

Skills that increase Boost Level at the start of own turn

Type	Name	MP Cost	Target	Skill Points	Exclusive?
Phys	Rip	7 MP	Self	-	Zodd
Light	Nirvana	6 MP	Self	-	Vishnu A
Almighty	Death Flyers	8 MP	Self	-	Beelzebub☆
Passive	Black Beckoning	Passive	Self	-	Black Maria
Passive	Bloodstained Divine Queen	Passive	Self	-	Kali A
Passive	Descent of Ice and Snow	Passive	Self	-	Sukuna-Hikona A
Passive	Dragon Chief	Passive	Self	-	Pendragon
Passive	Halo of Hallel	Passive	Self	-	Flauros Hallel
Passive	Omniscient Guidance	Passive	All Allies	-	Gemori
Passive	Sword of Hallel	Passive	Self	-	Ose Hallel

Skills that increase Boost Level after use

Type	Name	MP Cost	Target	Skill Points	Exclusive?
Phys	Dragon Slayer	6 MP	Self	-	Guts
Phys	Heavenly Sword	6 MP	Self	-	Ose Hallel
Phys	Violent Slash	6 MP	Self	-	Susano-o A
Fire	Aztec Pulse	6 MP	Self	-	Quetzalcoatl A
Fire	Eruption	7 MP	Self	-	Surt A
Fire	Hell Blaze	6 MP	Self	-	Cerberus A
Elec	Thunderous Hammer	6 MP	Self	-	Thor A
Force	Barbed Spear	6 MP	Self	-	Cu Chulainn A
Force	Gale Talon	6 MP	Self	-	Garuda A
Light	Baptisma	6 MP	Self	-	Flauros Hallel
Dark	Fangs of Vengeance	6 MP	Self	-	Tiamat A
Ice/Force	Ruler of the Skies	7 MP	Self	-	Pendragon
Almighty	Third Eye	8 MP	Self	-	Shiva A
Support	Noblewoman Aid	6 MP	Self	-	Gemori
Support	Virtuous Prosperity	6 MP	Self	-	Lakshmi A
Passive	Chief God's Rage	Passive	Self	-	Odin A

Boost Level benefits

Skills that benefit from Boost Level

Type	Name	MP Cost	Target	Skill Points	Exclusive?
Phys	Dragon Slayer	6 MP	Self	-	Guts
Phys	Rip	7 MP	Self	-	Zodd
Phys	Violent Slash	6 MP	Self	-	Susano-o A
Fire	Aztec Pulse	6 MP	Self	-	Quetzalcoatl A
Fire	Eruption	7 MP	Self	-	Surt A
Fire	Hell Blaze	6 MP	Self	-	Cerberus A
Elec	Thunderous Hammer	6 MP	Self	-	Thor A
Force	Barbed Spear	6 MP	Self	-	Cu Chulainn A
Force	Gale Talon	6 MP	Self	-	Garuda A
Light	Nirvana	6 MP	Self	-	Vishnu A
Dark	Fangs of Vengeance	6 MP	Self	-	Tiamat A
Phys/Elec	Divine Spear Gungnir	6 MP	Self	-	Odin A
Almighty	Death Flyers	8 MP	Self	-	Beelzebub☆
Almighty	Third Eye	8 MP	Self	-	Shiva A
Support	Noblewoman Aid	6 MP	Self	-	Gemori
Support	Virtuous Prosperity	6 MP	Self	-	Lakshmi A
Passive	Black Beckoning	Passive	Self	-	Black Maria
Passive	Bloodstained Divine Queen	Passive	Self	-	Kali A
Passive	Descent of Ice and Snow	Passive	Self	-	Sukuna-Hikona A
Passive	Dragon Chief	Passive	Self	-	Pendragon
Passive	Halo of Hallel	Passive	Self	-	Flauros Hallel
Passive	Sword of Hallel	Passive	Self	-	Ose Hallel