I am stuck in Enigmatic Grotto due to this one reason: The battle with the three trolls, in which your first pet gets knocked out. Does anyone have a strategy for defeating the trolls?

I was stuck there too. What I did is grind my pets to level 30-ish, and carried a revival draught for the Sylesti that go KO'd at the start. Other then that though, i guess the elements helped. I had an earth, a light, and a wind (though a fire might have been better).

I was stuck there for the longest time. But I saved my money so I could get a third party, who I would still have two pets to fight with. Then whenever mend was available, I'd heal them. I had fire, water, and earth. My water one was taken out, but my other two managed.