This is where you can edit the gear of your entire team and make it stronger. Leveling up and refining your gears is one way to raise your might.
The Advance Section is where you can advance the type of gear that you have. In the bottom example you can advance the Brightness Coronet into the Blaze Coronet. You can do this for every gear item and for every character. Doing this will add to your might.
You can refine gear with Gear Refine Stones. You can get the stones from the Item Shop, Team Competition, or the Trial Tower. Refining a gear will make it stronger and thereby give you more might. You can each gear for every character.
Only gears of Elite quality of better can be equipped with Crystals. (Elite quality is Yellow, for gears it is called "Brightness"). Each crystal comes with a randomly generated attribute which can only be changed/made stronger with crystal polish.
Crystals with different qualities have different attributes:
Crystal polish unlocks at character level 90. It can reset the attribute of the gear that you choose but whether it makes it better or worse is random. Luckily, you can choose to accept the new attribute or not; Click "Replace Attribute" to replace it and click "Abandon" to keep the attribute that you have.
Every Gear and be inlayed with a gem and it doesn't matter how rare the gear is. The gear just needs to be leveled up to 36, 45, and then 50 before you can equip a gem into each spot. Each gear item only takes a specific type of gem, but the process is automated so you only need to find the gear that has a red dot on it. But you will need to go through each character in order to find the gear with the red dot.
Fusing gems together will make the gem stronger and then you can inlay a stronger gem into one of your character's spots. To fuse you need 3 gems of the same type and same level to fuse a gem. Afterwards you can go into the inlay section and give one of your heroes the newly fuse Gem.