score:2
Unless you are going to be providing him with support, financial or otherwise, then there is no need to provide supporting documents, especially financial documents. Providing unnecessary documents can show a lack of understanding of the visa process, which will hurt the application. On the other hand, anything that adds credibility to an application can be helpful.
If your relative is staying with you, then a letter stating that you will be giving him accommodation (and ideally some evidence showing that you can provide it) would be helpful. If his stated reason for coming to the UK is to visit you, then if he is able to show that you exist, that you are related to him, and that you are in the UK legally (i.e. a citizen) will also help his case.