[Xero Shade]

So, I'd like to suggest that when a certain event happens in battle (I.e., a crit), your character says something pre-set (that can be changed by you).

Person A attacks Person B with Weapon A! Crit!
Person A: Taste my steel! (Preset)
Person B riposte's!
Person B: Not so tough now! (Preset)
Person A uses a potion!
Person A: I need a bigger edge! (Preset).

Just some ideas that came to mind.

Possible battle text trigger conditions:
Score a critical hit
Receive a critical hit
Drop below 50% HP
Drop below 50% FP
Riposte attacks
Stalemate parries
Defeat an enemy
Fall unconscious
Heal yourself
Heal an ally
Receive a heal from someone else
Be revived from unconsciousness by someone else
Die Hard activates

^Quoted from LadyLightning.