Awakening your monsters will turn them into a new form, and possibly increase their rank. To get the essences for awakening, go to the Cairos Dungeon and go to the Hall of Magic and the hall of (fire/water/other element) for the other element of essence that you need. Once you have enough, you can awaken a monster, no matter what experience level they’re at.
Build the Fuse Center from the shop and you will be able to fuse same elements together in order to make a rarer version of that element. There are low, medium, and high strength versions of each element. The higher the rarity of the monster, the more rare the element that you will need.
See the Fusion Hexagram in the store? It’s not available yet but when it is, BUILD IT. When you build it, you will be able to fuse monsters together in order to get a rarer monster. It will no doubt be unlockable only much later on in the game, but it gives you yet another way to improve your monster squad.
Build your defenses as strong as possible. Go to the defense area in the Summoner’s Tower to put your strongest team members on the defense, and try to put in a good mix of elements so that they can take on any comer. And build new Arcane Towers as soon as you can. When you get attacked and you win, you’ll earn glory and arena points, even if you are offline, so that weekly prize can be higher without you even having to do anything.
Want a quick way to gain an experience level fast? Start buying the large rocks from the shop and putting them all over the place. Then clear them out, and you will earn 100 experience points apiece. This trick requires a whole lot of Mana, but it will earn very quick experience points. Plus, more rocks and trees will appear on their own, so clear them out when they appear.
Not happy with what you see in the Magic Shop? Go to it and unlock the locked spots, and start shopping off of them. The unlocked spots make it more likely that a rarer (albeit more expensive) item will show up. You might have to spend some crystals at times, but it will prevent you from having to spend crystals to refresh the list of items in the shop.