Cavalry

Achilles was initially freaked out by his left arm being completely destroyed, leaving behind only a mangle of squished meat and broken bones, but he soon collected himself. Now wasn't the time to worry about a broken arm.

As long as it remained intact, then he could recover it back to its original state. There was nothing to be concerned about.

After he quickly evaded the tentacle, Achilles' connection with his rotten shark severed. It was dead. He quickly commanded the reverse merman to swim away as far as possible in order to avoid another casualty.

After ensuring the merman's safety, Achilles shifted his attention back to the deadly tentacles that were ready to claim his feeble life. The Kraken must have realized that he was the mastermind behind its wounds and was now trying to kill him at all costs.