Final Fantasy Rebirth » Final Fantasy X » Overdrive Modes
Stoic
Stoic is a good overdrive for fighting stronger enemies as your overdrive guage charges as you take damage.
You get this Overdrive Mode as default.

Warrior
Your overdrive guage charges when you attack an enemy when using this mode, you recieve this mode from taking damge from enemies.

Comrade
Your overdrive guage charges as your allies take damage, this overdrive mode is gained when your party takes damage.

Slayer
Your overdrive guage charges when you defeat an enemy, however this is usuless when fighting against one enemy. To get this Overdrive Mode you must defeat as many fiends as possible with one character.

Hero
Using this overdrive you overdrive guage charcges from defeating strong enemies, to get this mode you should defeat strong enemies in places like Omega Ruins.

Ally
Overdrive guage charges overtime, to get this you should use more turns than usual with a character by casting magic such as Haste.

Daredevil
Overdrive guage charges when a character is on critical HP, to get this fight often on low HP.

Tactician
Your overdrive guage charges when you inflict a status disalignment on a fiend, to get this use Status inflicting attacks more often.

Avenger
Overdrive guage charges when a character dies, to get this you must let your characters get KO'd often.

Sufferer
Overdrive guage increases when you have you status changed.
Allow a character to take as many status changing attack as possible. A good way to get this would be to fight a fiend that inflicts Stone or Poison.

Victor
Gained from fighting lots of battles, your overdrive guage goes up as you win battles.

Victim
Overdrive guage charges as you get hit with Status attacks, this is learnt automatically as you progress through the game.

Coward
Overdrive guage charges when you use Flee to escape a battle.

Solo
Your overdrive guage raises when you defeat a battle with one character, the best way to do this is have the other characters retreat.

Dancer
Overdrive guage increases when you dodge an attack, the best way to get this is to have the Weapon Ability 'Evade & Counter' and get as far around the Sphere Grid activating as many Evasion nodes as possible.

Healer
Your overdrive guage rises as you heal more people in your party, to get this use healing magic or items often in battle.

Rook
Obtained by using spells such as 'Protect' on characters, your overdrive meter raises as you use defensive magic.