Although I've decided to deal with the Hundred-armed Monster, it's not easy to kill a monster equivalent to a Tier Three Legendary Knight, so we definitely need to make thorough preparations.
With just the combat strength that Sunan currently has, there's no absolute certainty of being able to take down the Hundred-armed Monster.
"Luckily, that Hundred-armed Monster shouldn't be coming to the surface anytime soon."
From the conversations among those Kobolds, it seems the Hundred-armed Monster likely drove its minions out to raid due to a lack of food. After Sunan's slaughter, there are now plenty of corpses in the cave, which should be enough to feed the Hundred-armed Monster for a while.
During this period, he can prepare ways to deal with the Hundred-armed Monster.
For this, Sunan already has some ideas.
The unforeseen incident hasn't affected Sunan's scheduled plans.
After attending Kei's wedding, he devoted himself to meditation and study as usual.
