The player can leave the ruins and the count will not reset. Tonberry King will not appear in a battle where the Tonberry is defeated by carding. Tonberries killed in Ultimecia Castle also count toward the threshold for calling forth the King, but the King cannot appear there.
Tonberries will counter most attacks with Everyone's Grudge, an attack that deals HP damage calculated by the number of enemies the character has killed multiplied by 20, though it will stop using this after walking forward twice. After it walks forward five times, the Tonberry will randomly attack a party member with its knife or it might fall over, losing a turn.
As the Tonberry's HP and defense are formidable, one may consider using Demi or the summon Diablos, as it is not immune to fractional damage. Doomtrain or Meltdown can cast Vit 0 on the Tonberry to knock down its defense and make it easier to defeat. Other defense-ignoring attacks include Quistis's Micro Missiles and Irvine'sArmor Shot. Keeping Irvine in low health and using his Limit Break is one of the fastest ways to amass the required kills to summon Tonberry King. If the player is using Vit 0, a quick way to defeat the Tonberry afterward is to junction for high Strength and use Mad Rush; however, when the player is getting near the threshold for spawning the King, they should stop using Mad Rush as not to enter the boss battle in berserked state.
MuggingChef's Knives is a quick and easy way to obtain 100 Deaths for every character as one refines into 30 Deaths with Siren's L Mag-RF. Chef's Knives also refine into AP Ammo (Ammo-RF), useful for using the low-health Irvine tactic against them.
Tonberry is a Level 3 Monster Card in Triple Triad used for playing the minigame and for turning into Chef's Knives with Quezacotl's Card Mod. Ad the card can be obtained much before encountering the enemy itself, it is a good card for farming as it refines into AP Ammo and Death spells.