Attack and enemy from the back to get bonus damage. Some skills, such as Roll, will allow you to do this easier. To do this, attack the enemy once to lock your character in its direction, then use Roll. You will roll through the enemy and end up behind them, ready to attack from the rear.
Crystals
Crystals are the game's premium currency. They are used to purchase high end items. They can be obtained through several methods. Each stage has three objectives that can be completed. A Crystal will be awarded when all three of them are done. Additionally, because the objectives vary based on difficulty setting you can earn a total of three Crystals per level by completing the objectives under the easy, hard, and elite difficulty settings. The daily bonus for logging in will occasionally reward you with Crystals. The more consecutive days you log in, the better your rewards will be. The Infinite Dungeon is an endless monster challenge. You can try it as often as possible, however you will need to wait after five attempts. The longer you survive, the better your score. A leaderboard keeps track of every player's score, and a Crystal award is given weekly to the top players. Special events are held from time to time that may include Crystals as a reward. Play and complete the Continuation quests to earn Crystals.
Defense
Most enemies will attack by just approaching you and swinging. Remain in motion to avoid them, especially with your Archer and Sorceress because they are ranged. Use the Roll skill during bad situations to move through enemies. It has a short cooldown and usually will be available for use.
Elements
Each guardian has an elemental type. Use the an element they are weak against to get extra damage. Fire is stronger than Grass. Grass is stronger than Water. Water is stronger than Fire. Light and Dark are neutral against each other.
Enhance stones
Enhance stones are awarded after completing quests or leveling up. You can use them to upgrade equipment for your main hero. Do not bother upgrading common equipment or other pieces that will be replaced.