Merchant and Blacksmith
The Merchant and Blacksmith is a powerful attacking job, able to dish out the most damage. The Magnitude skill, combined with good strength and dexerity stats, is probably the best attack in the whole game. It will be very useful in the Mirage Tower. Along with strength and dexterity, you should also boost vitality for the Merchant/Blacksmith. If you have a Phreoni card, you can use that instead of focusing a lot on dexerity.