It usually opens each fight with Freezing Dust, which inflicts Frozen on one target. This effectively disables them for most of the battle, which wastes precious time. It also attacks with Snowstorm, Blizzara, and Hit, a physical attack. It is weak against Fire and Lightning, so Fira and Thundara work well, but it counters spells with Silence. This Silence spell has the same graphical effect as the gray spell the party can use, but Naude's version is not reflectable and not Runicable.
Since the player is on a time limit, one of the two quickest ways to defeat the Naude is to either cast Rasp to damage its MP, killing the Naude when its MP reaches 0, or cast Imp on it, which will prompt it to flee after curing the status with its own Imp spell.
1st Turn: Attack (33%) or Freezing Dust (33%) or Hit (33%)
2nd Turn: Attack (66%) or Blizzara (33%)
3rd Turn: Attack (33%) or Blizzara (33%) or Snowstorm (33%)
If attacked by "Magic":