How are you supposed to complete the "Giant Nemesis" quest?

You get this quest at around the point in the game where you hit level 46~48 (at least I did), and it's marked as short-term, so I can't put off completing it--progressing the story any would probably mean failing the quest.

But the quest requires you to go fishing in an area full of level 56 enemies, and I can't manage to do any significant amount of damage to even one of them. So how on earth are you meant to fish up a fish while the three to five of them that invariably notice you running to the pond, no matter how stealthy you try to be, are running after you? Is there some trick to this, or am I just vastly underlevelled?

Everything I found searching for an answer online was people having trouble with catching the fish, but I can't even get to the pond where you're supposed to fish!

Solution 1:

Well, after not getting any answers here I decided to try again, and the solution appears to be... very straightforward. Just bait the individual enemies away one at a time (two is maybe manageable), and you can actually manage to take them out by spamming skills, though you have to be very careful not to get hit as they hit hard--I had them taking off about a third of my health bar with each hit. Once you've cleared out the ones near the pond, you can fish up the fish.

I think my problem was seeing how hard they hit and thinking there's no way I can beat that, without noticing that you can actually do a respectable amount of damage to them if you can just avoid getting hit.