After Klarth/Claus contracts with the Sylphs, you find a girl who requests your help.
When you are ready, go to the town north of Bart's house. Walk up through the town and you will find Lia. She will join you as a non-playing character. She will not join you in battles. Go north from Harmel to Venezzia.
From the entrance, go right, cross the bridge, and go around and into the house. On the first floor, talk to the woman standing by the fireplace to find out where Demitel went. You need to talk to her in order to reach the next part of the game.
Now go upstairs in this house and talk to the old man. You need to talk to him to be able to get a new spell later.
Now you can continue following Nancy and Elwyn's story. Nancy is in the inn. When Elwyn and Nancy are in front of the fountain, leave town and go back in, then go upstairs in the trading company to find them. After the scene, go out onto the balcony of Elwyn's father's office to find a chest (Protect Ring). Then go out and talk to Elwyn, who is standing in the shadows north of the fountain.
In the northeast part of town, you will find a gondola for hire. You need to ride the gondola to reach the weapon and armor shop.
In the weapon shop, by the Corsesque for Cless/Cress, even though you will get one for free later. Remember to take advantage of the Corsesque's stabbing power by pressing up when you attack.
You can also get a Gem Rod for Mint.
In the armor shop, you might not want to get the Armet Helm, because you will get one free later.
Talk to the other people in the armor shop. One of them will sell you the Tempest combo.
You can ride the gondola to the item shop, or you can go there for free by using the southern entrance into the harbor, then go down and left from there.
Be sure to buy food at the supermarket. I do not recommend the Steak or the Twinkies. You will be able to rest for free soon, so don't bother spending money at the Inn.
If you do not have at least 1600 gold, go outside of town and fight battles until you do. Then use the northern entrance to the harbor. If you talked to the woman in city hall about Demitel's whereabouts, you can now hire this boat to go to Demitel's island.
After you arrive at the island, you can rest on the boat for free.
There are two chests on the dock. The one on the left contains a Mixed Gummy. The one on the right contains a ?Book, but it turns into a weak weapon, so you might as well leave it in the chest.
Just outside of the mansion, open the chest to get a Spy Lens. Go into the mansion, and go to the left. The first door has a save point. Go south from there and you will see two doors. The one on the left is locked. Go through the unlocked door to find the door to Demitel's library.
In Demitel's library, go to the upper-left corner of the room and open the chest that is hidden behind a vase. It contains Savory. Then check the shelf behind that to get a Magic Key.
Go back to the first room of the mansion and go to the right. Go through the door on the right to find several chests. From top to bottom, left to right, they contain an Apple Gummy, Verbena, Savory, Apple Gummy, Elixir, and 430 gold.
Then exit the treasure room and use the magic key on the upper door.
In the garden, there are random enemy encounters.
Walk up to the big tree in the center of the garden. You will soon fight a mini-boss, so you should prepare now. Equip Cless/Cress's Lightning Bolt skill. Change Klarth/Claus's tactic to summon the Sylphs. Leave Mint's tactic to Value HP over TP. Check the tree until the battle starts.
Use Lightning Bolt against this enemy. If you have trouble, you can manually make Mint cast Hammer.
Demitel's Island, Part 2
When the tree is gone, change Klarth/Claus's tactic to not casting spells. Go back into the first room of the mansion. Open the middle curtain, then check the middle prism twice, and check the left and right prisms three times. A new door will open. Before you go through, go back to the ship to heal up.
Then go back and use the passage that you just opened. At the first fork, go left to find a chest (Reverse Doll), then go to the right. At the next fork, go down to find more chests. The one on the left contains a Corsesque and the one on the right contains an Armet Helm. These are good to sell if you already have them. Then go back to the fork in the path, and go up this time. Before you go through the door, prepare for the battle with Demitel.
Be sure to equip Cless/Cress with a Reverse Doll or two, equip Mint with a Mystical Rune and a Talisman, and equip Klarth/Claus with his Opal Ring. Have Klarth/Claus's tactic set to summon the Sylphs. Have Mint's tactic set to value HP over TP. Cless/Cress will use Lightning Bolt and his best close range skills.
Try to constantly attack Demitel to prevent him from casting powerful spells. Cless/Cress should try to quickly kill the other monsters so he can focus on attacking Demitel without worrying about being attacked from behind.