Think.

Since killing a hero didn't get you nearly as much of a reward as you hoped it would, you start to rethink your strategy. In what other ways could you become stronger, or at least become able to move away from this cave? For a long time, you don't come up with any idea's, let alone good ones. Killing heroes really seems like the most efficient way to grow.

After a while, you get tired and remember the barbarian's strange words. Only now do you realize that you never found out his name. Not that it matters. The words confused you then and they still do so now that you have more time to think about them. He said something about a quest you apparently gave him when you asked him to help you. That shouldn't be possible. There is one quest you can give heroes and it is definitely not the quest the barbarian was talking about. The quest you can give sets heroes off on a journey to find ancient artifacts in hidden tombs and temples so that they will find out what happened to the Kappas and several other creatures on the Archipelago. How they react to that information can lead to them acquiring one of the new classes, one for a "good" and another class for an "evil" response. You haven't given that quest to any hero yet.

If your request to the barbarian really became a quest for him, that could mean that you can give any quest you want to heroes. That could be very useful. If you knew how to control the exact reward and clear conditions for the quest you give them, which you did not control last time. The only way you can think to really learn how to control this would be to practice it. Which means you'll need to find heroes and offer them quests. Quests to which you might not fully know the rewards or clear conditions. You see many problems that could come from that, most involving you dying. It does seem like a safer and possibly quicker way to grow than hoping for stupid lone adventurers to come to your cave, however, so you resolve yourself to try it.

You sneak out of your cave and hide behind some rocks. Peeking out of your hiding place you look at the world outside your cave, which is a large grassy plain where the entrance to many caves and caverns are hidden by seemingly innocuous piles of rocks. As you peer over the grasslands, you dismiss the first adventurers you see as their clothes are adorned with skulls. You don't need (or want) a white knight, but you don't want to associate with some evil maniac either. After some time of looking for heroes to test your quest giving powers on, you spot an interesting party that probably suits your needs.