Check this guide for everything you need to know about Keyblades and Medals in Kingdom Hearts Unchained X!
Your equipment and how you fight works differently in Kingdom Hearts Unchained X than it does in most Kingdom Hearts games. Each Keyblade has multiple slots for Medals. Each Medal is an individual character, has a certain attack power, rank, and skill.
I'm going to explain how Keyblades and Medals work and give some tips on which to use and when to use them. If you want more general info, check out the Kingdom Hearts Unchained X Beginner Tips and Tricks.
There are currently 5 Keyblades you can get in this game. All Keyblades will use certain materials like ore that you can get anywhere. Each Keyblade will also use materials you can only find in certain places.
I wouldn't try leveling them all up because you will run out of the Mythril Shards and Orichalcum, which can't be farmed right now. I would focus on the 3 specialist Keyblades, Treasure Trove, Lady Luck, and Three Wishes. These give you the most overall strength in each category and most missions won't require multiple types of Medals.
Starlight is great if you need a Balanced Keyblade, the the boost you get is much smaller than the others. As you are going through the Story quests, and most of the Special quests, you will want the specialized Keyblades.
To level a Keyblade, go to "Equipment" from the menu, then select "Keyblade LV UP" on the Keyblade you want to level. Select "Strengthen" to level it up. It also lets you know how many materials it requires and how many you have for each upgrade.
Medals can get skills, such as attack or defense boost, or cause status effects like Sleep or Paralysis.
I suggest getting the Attack Boost and at least 1 Defense Boost to complete some of the optional objectives.
For the Medals, it is a good idea to get at least 1 Medal that attacks multiple enemies and 1 that attacks 1 enemy. Shoot for those that say "Moderately" or "Extremely" powerful.
Personally, I have one Medal in my Keyblades that gives a Strength boost as their special attack. It is great because it makes your other Medals stronger and attacks a single target at the same time. Try to get one that boosts for the whole turn if you can.
If you want to gather materials and defeat raid bosses easily, focus on attack Medals with strong Special Attacks. The idea is to defeat enemies in 1 turn so the healing Medals are not as useful.
If you fuse Medals that have the same name and rank, it powers up their Special Attacks. You can tell how many times you can do this by looking at the circles underneath the Special Attack's name.
The goal is to fill a Keyblade with at least 5 star Medals. The higher the rank, the higher the cost to put the Medal in your Keyblade.
As long as you continually upgrade the different Avatar Boards, you will have a high capacity. 6 star Medals cost a lot so you will only be able to have 1 in each Keyblade for a while. They take many Exp medals and evolve Medals that you can only get from daily Special Quests, so it may be a while before you get 6 star Medals.
That's all for my Keyblade and Medal guide. Let me know if you have any questions or visit my Kingdoms Hearts Unchained X Beginner Tips and Tricks for more help!