This is an easier one, just use any physical weapon such as a sword or axe.

This dude is a pain in the a**, what you have to do is use bomb cards or fire magic cards on the chest. He will then eat the card you gave him and he will spit out an enemy which correlates to whichever card you have him. I.E., if you give him a fire magic card then a fire elemental will spawn, if you give him a bomb then a cat holding a bomb will spawn. What you want to do is then attack the enemy that the chest spawned and if the enemy is in the right place (in front of the chest if it is a fire elemental or on either side of the chest if it is a bomb cat) the defeat of the enemy will damage the chest via explosion or burning. Repeat until the Giant Chest is done.

Each time you kill one of the heads it will respawn in the closest location to where it was killed. You can either use swords to take out an individual head and then book it to the staircase to escape or you can kill the three heads simultaneously by clearing all obstacles and enemies in the way of the heads so they are all in the front row. Then you must use an axe to kill the three heads at once.

This enemy will turn you to stone any time you attack it and revive stone enemies around it. You have to defeat Medusa in the same way you would the Giant Red Chest; by using your surroundings to defeat her. Search for bomb cards or axes and attack the enemies beside her as to hit her by connection and not directly. Or attempt to attack enemies who have bombs, fire elementals, or the like as to damage her indirectly.

Once you approach the giant, use a confidence (healing) card on the giant. If you don't have a confidence card just keep clearing teardrops until a chest spawns and grab some from there.