Flexible Sentry

This boss as two sides; one side has clubs as weapons while the other has swords. The clubs are slower but can deal bleeding damage while the swords are faster and has wider range. Use the pole in the middle to separate yourself from the boss. Even with this limited space, you should be able to keep a safe distance from them, especially if you're using spells or miracles. Melee fighters can roll out towards the pole and it will stop the bosses combos most of the time. Just anticipate their movement and evade at the right time before their weapons connect.

You'll get the Flexible Sentry Soul after defeating it. Head to the next room and loot the chest to get a Pyromancy Flame and Fireball. Next, examine the compass to operate the ship and head to the next land.