There are a few options, but the difficulty here is trying to block this particular user without blocking others.
The IPs you have listed are all in the same block - assuming that these are the only IPs you have seen used, you could add 121.54.54.* to the IP blocklist - this would block any IP that started with the first three octets.
You could also add a username block, maybe Team Elite*, or *elite*.
Unfortunately both the above blocks are not too difficult to get around, but it is very difficult to try to block a user anyway. It is very easy to get a new email address, IP, and username - in which case any blocks will be bypassed.