You can use your major parts to create Crystals or Med/Energy Packs. Your Pharmacy level determines how many Med/Energy packs, you can make per turn while your Fusion level determines how many Crystals you can fuse per turn.
If you do not want to create your parts or items, you can always see what items or parts are available for purchase in the Trade Market. Creating items such as med packs and crystals are a great way to earn lots of Mira from the Trade market.
In the V.I.P room you can play slots to earn V.I.P tokens or exchange your V.I.P tokens in for very rare prizes such as Key Bot Companions, Honor Badges, Blessed Amulets, Attribute Points, Mira and more. Key Bot Companions can be equipped to aid your character in battle and heal your character randomly after each confrontation. You can use your V.I.P tokens to level up your Key Bot at any time. Your Key Bot's attack power and healing ability increase each time it is leveled up.