Unobtainium Enhancement is used to increase items tier. Each Unobtainium tier increases the item Bonus tier by 10.
An item tier is calculated by (Rank / 10) + (Unobtainium Count * 10).
Unobtainium enhancers will be mainly obtained from 3 sources:
Weapon Level 5 Enhancers (Infinite): Will be obtained as a Battle Point reward.
Armor Level 5 Enhancers (Infinite): Will be obtained as a Battle Point reward.
Accessory Level 10 Enhancers (Single use): Will be obtained by reaching 2400 streak in Spooky Crypt.