Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
```
supercell reserves the right , at its discretion , to change , modify , add or remove portions of these terms of service , its privacy policy and other relevant supercell policies at any time by posting the amended terms on the supercell service . 

```
. OPTIONS: ['None' 'Contract by using' 'Unilateral change' 'Limitation of liability'
 'Choice of law' 'Jurisdiction' 'Arbitration' 'Unilateral termination'
 'Content removal'].