So, I'm at the part where you encounter C-something (I wanna say Cerneth, but I'm not sure that's it), and I've died twice attacking him, using up my revives in the process. Is there a best way to battle this guy, or do I just need to grind?

Also, it wouldn't let me use the lesser revives (20% health ones I bought from the market) in battle. Yet the description says nothing about not being able to use them in battle. More than that, is there a way I could get some better revives right now?

Oh, and I should note that my party was Rocker and Philip at the time. I've been thinking of replacing one of them with Artemis. Should I, or does it really not matter?

Hmm..well, your pets are not really ready to do that. Their equipment is poor and I am not sure but you should have another pet in your party,just go to Elsior's Haven and go to the Sylesti Plaza to unlock an additional slot.

Also, I would suggest not having a healer in your party right now because you need all the battle help you can get so I would suggest having a air/water/shadow pets and keep fighting in other areas until you either can buy better stuff or acquire them from battles.

I noticed you have a fire pet in your party, that is good but you need something to increase its dexterity as that helps boost the effectiveness of its attacks.

Don't worry, when I started out I just rushed through and my party really paid for it. Cerenth isn't easy and your team needs more leveling and equipment.
I would send you some items but the ones I have are not tradeable.

In short, train more to level up and never underestimate the power of a blocking move.

You should look here :)
Quite a helpful thread.
https://www.sylestia.com/forums/?thread=44033

Thanks! Been doing that! Update below.

Update: Gotten some new equipment, and a couple of new Sylestis. The team I'm thinking of using is Sun (Health Water) and Artemis (Intelligence Light). Gonna grind Sun to at least level 15 to equip him with some higher level equipment I have in my inventory (both uncommon, though, couldn't find anything else on the trade broker that I could afford).

Also, I still haven't gotten answers to my other questions. Why couldn't I use the lesser revives during battle when it doesn't say anything about not being able to use them in battle? And where can I get better revives?

I'm going to assume you were trying to use the lesser revives after the pet was knocked out? If so, that's a bug, and should be reported. You can get better revives in Ethernia's Market, which you can access in the third region - you may be able to purchase them from the Sanctuary of Saerielle, though, but I'm unsure of that.

Okay, I'll report it. Just wanted to make sure I wasn't doing something wrong. Thanks for the info, too!

(Note: I have now beat Cereth! Yay! On to the next adventure!)

Congratulations, and good luck on your journeys!

There is a cooldown on using items in battle, so you may have been using one too soon after a previous use. But if they weren't working at all that would be a bug,

Oh, wow, this is an interesting coincidence. I literally just bought one of your for sale pets, then I come to see the ping I got and it's you!

Anyway, I do think it was a bug, because I wasn't getting the message about the cooldown.

Just level up your Sylesties some, lvl 19-20 and you should have no problem, as long as you give them good gear.