In the Shin Megami Tensei franchise, Tarunda typically decreases the physical attack power of all enemies by one stage and lasts until either the battle ends, an enemy is killed, or removed by a debuff removal skill such as Dekunda.
In Shin Megami Tensei III: Nocturne, the debuff is permanent and can stack up to 4 ranks. The attack debuff and the attack buff (Tarukaja) are separate variables, so although they stack with one-another and can neutralize each-other's effects, they still can only be used 4 times each unless one of the stats is reset with Dekunda or Dekaja.
In Shin Megami Tensei IV, Tarunda lowers the enemy faction's attack power by 1 rank, and stacks up to 3 ranks. Each rank lowers the inflicted party's attack power by 20%, with the minimum reaching 60%. It stacks multiplicatively with other buffs, Rakukaja included. (1.6*1.6=2.56)[1] The buff and debuff statuses are singular, rather than individual, so if the target's attack is increased by 1 or more stages, Tarunda will directly decrease it without the need of Dekaja.
In Shin Megami Tensei V, Tarunda is single-target, and lowers their Attack power (Physical and Magical) by 1 rank for 3 turns. The debuff can stack in 2 ranks, and debuffing each time resets the timer of the debuff. On the first rank, the damage is reduced by 4/5, while on the second rank, it's 7/10. Rakukaja and Tarunda stack via multiplication.[2]
In Soul Hackers 2, Tarunda lowers the attack power of the enemy faction. The effect doesn't stack in ranks, and normally lasts 3 turns, but it can be extended to 4 or 5 with Mistiques.[3] Casting the skill again will replenish the timer.
In the Persona series, Tarunda decreases one target's attack power.
In Persona 3, Persona 4 and Persona 5, Tarunda lasts for three turns.
n Persona 3 and Persona 4, the attack power of affected enemies is decreased by 2/3 (The formula is 1/(1+0.5), where 0.5 is the multiplier for attack boosts, hence countering Rakunda directly). If stacked with Rakukaja on the attacker of the user, the attack power is halved (1/(1+0.5+0.5)).
In Persona 5, the damage reduction of Tarunda is most likely 7/10. It most likely stacks multiplicatively with Rakunda, granting a result of 49/100. Casting the same skill again will extend the timer by 3 additional turns, up to a maximum of 15. Tarukaja directly cancels out the user's attack debuff, regardless of the remaining duration
In Persona 5 Strikers, Tarunda lasts for a certain period of time. Under default circumstances, it lasts 50 seconds.