To do this with Sharline, you have to find a plant critter that appears near the first crystal she sees. Kill this critter and it not only drops a Blue Fruit every time but also some money. The Blue Fruit allows you to spread five points among your stats. Walk through the crystal to the shop. This will reset the screen with the critter in it. Now when you return the same critter will be there, and killing him again will get you a fruit.
Darius is a little harder to do this with. He has at least one similar spot (that I have found), but requires more work to get pull off. In the upper shrine, in the far east corridor there is a Rock Golem. Killing him seems to drop a Red Fruit (twice as good as the Blue) each time he's killed. You still have to reset the screen with a visit to the shop, which this time is far away, but it can be done. The limit to stat increases from fruit is 200 for each. Darius' early Blue Fruit creature is the Paraday near the fountain.
Easy money
While playing as Darius, in the shrine under the castle there is a Save Crystal. Continue down the walkway you will fight a giant stone monster. Go left or right from that room you can find as many as four of these opponents. There is a good chance that they will drop a Palmira Ore, which sells for 1,000. They also drop Red Fruits on occasion, which also makes this location a good place to increase Darius' stats and equipment levels.
Darkforge Armor
In Darius's story, you have to fight a monster that appears in the reception hall. After you defeat this monster, the ground begins to shake and you go to the underground shrine. When enter, you will find a save crystal -- hopefully you have enough money to buy it. Enter the shop, go to the armor and purchase it. This is the best armor and greatly increases strength.
Defender Sword
In Darius' story, when you get into the coliseum and defeat the Boss, he will slam his sword into the ground and cause an avalanche. This will cause both of you to plummet downward. When you get on your feet, turn around and you will see a sword on the floor. Pick it up. It is the Boss' Defender Sword that he dropped after the fall.
Degulta
when you are transported to the coliseum in Darius's story, do not go inside yet. Instead, walk around the outside. You will encounter a monster with a Degulta. Defeat it to get it -- if you do not get it, you fought the wrong monster.
Heavenly Axe
In Darius' story, when you get to the abandoned road and defeat Djin, a bridge will apear. Go across the bridge and follow the path. You will enter a room with Sienna. Do not talk to her yet. Instead, turn right and pick up the Heavenly Axe.
Easy Easy Money
In the very beginning of both stories, at saramad hill, there is a small stone what looks like a box. if you hit this box 5-10 times a palmira bee appears. They are hard to kill straight on so to kill the bee use call of ice (Ice Armor level 3) or flame burst (flame skin level 3). They very often drop Palmira Ore which sells for 1000 p.p. and Dark Guide posts which sell for 200 p.p. and are needed to get to the hidden area. This works with both characters.