If you have 2 of the same character, you can burn one to create 1 character(+1) with considerably higher staking stats. Each account has a limited staking spot to incentivize NFT burning. Max is (+5), every+ is randomized % yield increase or decrease. You will need Onyx as the supernova catalyst.
Rikka is special, and her stars can be upgraded to (+5) with tokens instead. Burning another Rikka can give her (+6) for great benefit. Only Rikka can get (+6).

Supernova Catalyst

Need Onyx as Supernova Catalyst to burn and combine similar NFTs.

Void Crystal

Void Crystal can be burned alongside Onyx-es to revert unwanted effects on Supernova. Can be bought with $ANIMA.