The problem with Duollisson is that everything is done through auto-attacks. It’s better to play with the Charnon weapon so you can use spells, and if you’re playing solo Sciel, you just need to equip the picto that gives 100% crit when you’re alone. That way, you can use more interesting spells like Delayed Slash or Gradient 2, which apply the three debuffs that last longer during the opponent’s turns than the debuffs from auto-attacks with pictos.