FFX-2: Full Chain Achievement

Your chain will increase in battle as you connect multiple hits on an enemy before they can recover from the previous hit. Some enemies have longer recovery times, and the best enemy to do this against is Chac, a large serpent boss on Floor 80 of Via Infinito and as a regular enemy on Floors 81-84. This enemy has a large health pool (nearly 438k) so it can take a lot of hits. With all three girls in Thief dresspheres and auto-haste items equipped, you can use basic attacks and get this with little trouble. You could also wear Gunner dresspheres and abuse the Trigger Happy skill, but that's a bit harder to pull off. If you are over level 85-90 when you attempt this, you might kill the enemy before getting to x99, so try to get it done sooner than later.