FEF Heat System
Heat Points:
Heat Points are built from taking attacks from enemies, attacking enemies, staff healing or performances, with each granting 1 point. One can build up to five Heat in a battle; upon reaching five points, one cannot gain more Heat until some of these points have been expended. All Heat gained is lost upon being downed, though using Heat-restoring items to pick someone up grants them Heat, and Heal Surges automatically grant one point of Heat to the target if they were downed. Only a maximum of two Heat Points can be gained per combat.

Heat Mode:
Having five Heat points grants Heat Mode, granting +5 to Hit/Crit/Dodge/Eva and +3 Damage. When Heat is expended, Heat Mode is automatically lost and cannot be regained until one returns to full Heat. Some Bosses and Elite Units are permanently in Heat Mode, while others can enter Heat Mode upon reaching 50% HP, designated by the opponent being marked with [Heat Mode] next to their name. Enemy units with Heat Mode are more likely to use Heat Attacks and will use them to counter incoming attacks.

Heat Actions:
Heat Points can also be used up to do more powerful versions of actions accessible to characters.

Heat Attack:
Accessible by all units, Heat Attacks are stronger than normal attacks and cost 3 Heat Points each. Heat Attacks inflict 2x damage, higher than the average attack but lower than critical hits. Unlike normal attacks, Heat Attacks cannot miss, however, their critical rate is halved, with a maximum Critical Rate of 50. Bosses and Elite Units, however, only take 1.5x damage from these attacks; they are also capable of using their own Heat Attacks, which are unresisted; conversely, some bosses resist normal attacks and only take full damage from Heat Attacks, which will be specially marked. Heat Attacks also do not consume QL and do not double. Heat Attacks cannot be countered by normal attacks, but can be countered by expending points to use a Heat Attack of one's own. Heat Attacks do not themselves build Heat.

- Heat Combos: Activated with the permission of both activating characters, Heat Combos require two people to initiate them and for them to be adjacent to one another. When activated, three Heat Points are taken from each participating group and two enemies of their choice that can be targeted take x2.5 damage. Duo Heat Attacks require that their users have at least a B Support. Once a Heat Combo has been used by two units, those same two units cannot participate in another Heat Combo for one turn, even if their partners are different.

When used by units using Staves or Performances, the following stats are used:
E rank staves/performances: 8 MT, 0 Crit
D rank staves/performances: 10 MT, 0 Crit
C rank staves/performances: 12 MT, 5 Crit
B rank staves/performances: 14 MT, 5 Crit
A rank staves/performances: 16 MT, 5 Crit
S rank staves/performances: 18 MT, 10 Crit

Heat Surge:
Only accessible by units with Staff ranks and units with Perform or any variants of Perform. Heat Surges cost 3 points each and act as support versions of Heat Attacks.

- Heal Surge: When activated, Heal Surges heal a single target for x2 effectiveness and bypasses the halved healing when reviving an ally from 0 HP. Heal Surges can be used on the user as well. If the target has any status effects or debuffs, Heal Surges remove them. Downed units healed through Heal Surge also gain 1 Heat Point. Heal Surges can also be activated in response to incoming Heat Attacks by negating an incoming Heat Attack's damage only at the cost of the other properites of Heal Surges. Only accessible if the unit has Staff ranks. 

When used by units using non-Healing staves, the following stats are used:
E rank staves: 10+MAG
D rank staves: 15+MAG 
C rank staves: 20+MAG
B rank staves: 25+MAG
A rank staves: 30+MAG
S rank staves: 35+MAG

- Rouse Surge: When activated, Rouse Surges grants a single target +10 Hit, Critical, Evasion and Dodge until the end of the Phase and allows them to move again. Rouse Surges remove any status effects or debuffs on the target. Rouse Surges can be activated in response to incoming Heat Attacks to allow the user to counter with a Heat Attack of their own, counting as a Heat Attack. Only accessible if the unit can Perform or use variants of Perform.

Heat Counter: All of the above Heat abilities can be used to counter incoming Heat Attacks, which can be preempted by declaring one's intention to use a Heat Counter during one's action, which prevents the user from using Heat Attacks that turn and reserves the three points for a Heat Counter of the user's choice. If the counter is successful, the Heat Points are consumed and only the enemy takes damage from your Heat Attack. If no Heat Attacks hit the user, all Heat Points are refunded. While a Heat Counter is active, one cannot gain more Heat Points. Enemies preparing to use Heat Attacks will be specially marked using the [Roused] status, with different colors; green marks a Heal Surge, orange marks a Rouse Surge and red marks a Heat Attack, while [Rouse Counter] marks that the enemy will counter incoming Heat Attacks with their own.

Boost Tiles:
Boost Tiles increase the effects of Heat Attacks and Heat Surges. When Heat Attacks are launched from Boost Tiles, Heat Attacks do x3 damage instead of x2 damage, almost certainly guaranteeing the enemy will be defeated. Heal Surges fully heal any target that is healed from a Boost Tile, while Rouse Surges grant +15 instead of +10. Once a Heat Action is executed on a Boost Tile, the Boost Tile is used up and cannot be used for another Heat Action. Boost Tiles are marked using an orange triangle in the corner of the tile that disappears upon the tile being used up.

Heat-Restoring Items:
Energy Boost: Restores 1 Heat, 2/2 QL.
Energy Boost Plus: Restores 3 Heat, 1/1 QL.
Energy Boost Max: Restores all Heat, 1/1 QL.

Stamina Boost: Restores 1 Heat and 5 HP, 2/2 QL.
Stamina Boost X: Restores 3 Heat and 10 HP, 1/1 QL.
Stamina Boost Royale: Restores all Heat and 15 HP, 1/1 QL.