To kill the Captains in Fynn in Final Fantasy II Pixel Remaster, you can follow these detailed steps:

### Step-by-Step Guide to Killing Captains in Fynn

1. **Prepare Your Party**:
– Ensure your party is well-equipped with melee weapons. The Captains are Rank 5 enemies and do not run away, making them ideal for leveling up your weapon skills without immediately killing them.

2. **Choose the Right Position**:
– Position your characters in the back row to use melee weapons effectively. This will allow you to level up your weapon skills without immediately killing the Captains.

3. **Use Melee Attacks**:
– Engage the Captains with melee attacks. Since they are stationary and do not run away, you can focus on leveling up your weapon skills by repeatedly attacking them.

4. **Manage HP and MP**:
– Keep an eye on your party’s HP and MP levels. If necessary, use healing magic or items to keep your party members alive and able to continue fighting.

5. **Level Up Your Skills**:
– Continue attacking the Captains until your weapon skills have leveled up significantly. This will make future battles easier and more efficient.

6. **Optional: Farming for Gear**:
– If you’re looking to farm for specific gear like the Flame Bow or Toad Tome, you can continue to fight the Captains until you acquire the desired items.

By following these steps, you can effectively kill the Captains in Fynn while also leveling up your party’s skills and potentially acquiring valuable gear.