Well...um...first I need to know which guy. The name of the quest would help, and the name of the guy would really be good. Azteca can be challenging. At the end of this we may end up talking about effective gear and tactics too. You up for that?
However, the quest is still passable.
Let's go over some techniques to do.
Gear - What gear do you've equipped? Is it good including pets?
Deck - Is your deck of an adequate size with only the necessary cards/spells within it?
Go First - Since all your enemies know spells such as Efreet, you wouldn't want to be caught attacking into one. Going first will help in providing a much needed advantage.
Strategize - Very important. You're facing three mobs practically; but the boss just so happens to be weak to a school he has command of; . Now, I don't really recommend any converts but rather just powering through. Either use Fortify (to defend against their heavy attacks the first couple rounds) or Blade Up. I recommend fortifying though (Use Treasures if you have to) while you blade up (School Blade, TC School Blade, Elemental Blades, Sharpened Version etc.) Drop a Feint and a TC Feint on the boss while you're at it. Heal/Shield if necessary. Have both an enchanted Fire Dragon & Fire Meteor ready to attack in quick succession. Attack with Fire Dragon (Use Furnace if you can). If the mobs survive, and will not die in the next upcoming rounds from the burns, use Meteor. This should take them all out while leaving the boss just barely standing. Finish the boss with enchanted Low Rank Spells.
Tips - Watch for Efreet! Watch your health and the opponent pips. Always expect the worse and prepare and be ready to counter it. Use Treasures; place them in your side deck - You can also toss heals there and maybe a couple Fuels. Don't forget to shield if need be.
I just looked this one up on Wiki and it says the Fire wizard must solo this duel. You probably already knew that. It says you're not allowed to bring any other wizards with you. It does NOT say, however, that you can't use henchmen. I don't remember how I got past this guy but I use henchmen a lot. My choices would be Tartagna (Life), Purria (Storm), and Lambo (Death). Don't bring another Fire. They won't do anything. You probably also don't have to worry about Fire prizms. Let the other 3 take out the minions.. If you have already fixed the Sun and Star statues and you have your Sharpen Blade card, load yourself with blades both from your school and from other sources - pet, jewelry, knife. In the first round start stacking blades, ie; one school, one school sharpened, etc. Anyplace you have two alike sharpen one for stacking. You can also stack your traps the same way with Potent Trap charm. At that point your henchmen should have protected you long enough to set up for some good damage. Then, when you're ready to cast your best spell, you should have increased it's damage by a considerable amount. If you want more power than that you can also use your Wildfire, and don't forget to lay that fire around your feet. That's +25%. The minions should be gone by then and you can use King Artorius. Charm him too with your fist cards. I can never remember what they're called. The henchmen are in the Crown Shop. Make sure the "Usable" button is unchecked or they won't show up on the page. I hope I helped you just a little. I'll check back here to see how you did. Good Luck. Sydney Skyblood lvl 102 Fire
go to the bazaar, grab the best fire resist gear you can find. Blade up and use prisms. Use a spell like meteor first so you can kill the minions. Then, focus on the boss with single hits, blades, and prisms. Efreet will work very well. Bring some wand hits for those Efreets on you. The overall damage you receive should be negligent compared to what you dish out. Then just sell that gear off afterwards.